Many believe that Disney can change the existing reservation rules any time it feels like it. That is a misconception. The suggestion made to create a rule that basically prohibits home resort reservations for rental during the 11 month window is something that would be a material change to ownership rights in the governing documents and Disney cannot make such changes absent a vote of the actual members. The documents provide for a right to rent. They also provide that members will be treated the same for reservations, subject to owners of a resort having at least a one month reservation advantage over others for reservations at the home resort. The current 11 and 7 month reservation rule (a four month advantage) has been around since the creation of the second DVC resort (when OKW first opened a rule of 11 months and 10 months existed, but of course never got applied because of the absence of any other DVC resorts). The 11/7 rule works well for overall reservations and the systems designed to handle them and Disney likely sees no valid reason to change the current four month advantage to less.
All owners (including Disney for points it controls) are subject to the same rule: reservations shall be made on a first come first served basis. Absent a member vote, that rule cannot be changed to a rule that favors owners who are reserving for only their own stays. That rule prevents such things as Disney's creating reservation advantages in favor of those with a lot of points over those with not so many.
Renting is expressly permitted subject to a rule that a member cannot be engaging in a pattern of rental activity that shows the member is engaging in rentals for "commercial purposes." Though somewhat vague that is basically a term, as even construed by Disney, that prevents members from being in the business of renting. It does not, for example, prevent a member from using part of their points for family reservations and part for renting to cover dues. About 10 to 12 years ago, Disney created three rules that actually addressed a problem that existed at the time of members being in the business of renting: (a) if a member attempts to make more than 20 reservations during any given 12 month period, there will be a presumption that you are violating the commercial purposes rule and you will not be able to make more reservations absent establishing that none of your reservatiosn are rentals; (b) the transfer rule at the time which allowed a member who intended to rent to take in an unlimited amount of transfers per year was changed to allowing only one transfer; and (c) the rule at the time which allowed anyone to become an associate member to any number of other memberships, so the associate could make reservations using that other member's points, was changed to allowing one to be an associate member on no more than four memberships.
The assumption is made that a major cause of low inventory at 7 months out is members engaging in predatory renting by reserving 11 months out just to rent at favorable times for favorable rooms. It is actually that kind of predatory renting that was addressed 10 to 12 years ago by the three new rules noted above. At the time, there were professional renters, who controlled a huge amount of points, via ownership, via transfers in and via associate memberships, who were making large numbers of reservations right at 11 months out for highly sought after rooms (mainly studios at near park resorts) for high demand times such as Christmas, Thanksgiving, and others and then advertising on line to rent those rooms (this site even made changes to its rental board to prevent that by prohibiting members from advertising to rent reservations already made unless you were 30 days or less out).
The changes made more than a decade ago greatly reduced but did not eliminate predatory renting. Renting is perhaps one factor relating to availability at 7 months out, e.g., such as for race weekends, but Disney cannot stop it via the suggested rule to change the 11 month window rules, and going further than the rule changes it made 10 to 12 years ago could lead to legal challenges that Disney would lose.
Also, it is likely incorrect to assume that more restrictions on rentals are going to solve problems relating to availability at 7 months out. As I have noted in the past, there are basically two distinct DVC demand seasons at WDW, a low to moderate demand season that runs from the Monday after marathon weekend in Jan to late Sep, and a high to extremely high demand season that runs from late Sep to marathon weekend in Jan. During the low to moderate demand season many rooms including studios are often available at 7 months, including many at near park resorts such as BWV pool/garden view, Poly, and BLT lake view. Even BCV is available about 50% of the time, and even VGF and BWV boardwalk view studios can sometimes be found for a week particularly during the lowest demand times of the year -- Feb 1 to the Thurs before Presidents' Day, late Feb after the Princess half marathon weekend to second week of March, last week of April, and July 7 to 31.
The high demand that exists for late Sep to marathon weekend in Jan is brought about by numerous factors other than renting: (a) mostly ideal weather; (b) the Disney created events for Halloween and Christmas, and Food & Wine, which make that entire time desirable; (c) the ever-growing population of older DVC owners who can now take vacations not tied to school schedules and now want studios rather than the 1BRs or 2BRs they needed with kids; (d) the fact that the points required are, except for the holiday times, the lowest or second lowest of the year. Added to those are problems purposefully created by Disney that have resulted in extreme demand for near park resorts and studios at those resorts: (a) the creation of huge resorts not near the parks such as SSR that were actually sold by the sales force representing that one could buy there and then easily reserve elsewhere at 7 months out; (b) The ever-increasing purchase prices (bearing no relation to inflation) and points needed per night, such as for resorts like Poly and VGF, that render it impossible for many to buy more points than that needed for studios during the lower point times, and Disney adding to that demand further by lowering points required to be purchased and changing studios at near park resorts to sleep 5; (c) the modern DVC resorts at Poly and CCV which created large numbers of bungalows and cabins at a nightly point cost that only the rich can afford (e.g., the price one would need to pay to Disney for a week in a Poly bungalow every year exceeds $200,000), but allowed Disney to sell most of those points applicable to the bungalows and cabins to members who could only afford studios, thus legally "overselling" the studios and adding to demand for studios at near park resorts, and meanwhile Disney gets to rent a lot of time in those bungalows and cabins at 60 days out for profit: (d) particularly at VGF, creating too few studios while selling most of the points to those who could purchase only enough to get studios.
Changing the rental rules is not likely to resolve the existing problems with availability. Moreover, if you want to place blame for those problems, it should not be on members who rent but instead mainly on one party, Disney, which has done so much to cause the existing availability problems for the purpose of making more profits. Moreover, be aware that there is actually one party that is the best position over all others to do predatory renting, Disney. One might first think it is a good thing that Disney must follow the same first come, first served reservation rule as others. However, it is Disney that actually owns 2% to 4% of the points at any sold out resort and gets points via other means such as trade-outs and foreclosures, is exempted from the "commercial purposes" rule, and can during the 11 month window use home resort points to reserve rooms it later rents. The only thing that prevents it from using all those points during the 11 month window to reserve highly desired studios during highly desired times is one not even stated in any of the documents -- its fiduciary duty to act in the best interests of members as a whole, a concept which still allows the company to do a lot of things that some members may consider improper.