Simplicity doesn't necessarily mean faster (though I suspect in this case it will mean that, at least on average). It means less to think about. You don't have to investigate which brokers are reputable. You don't have to think about a selling price and you know exactly what you are going to get. There's no chance of the listing languishing longer than expected.
None of these things probably matter in practice. But, they might feel like they matter, and for some people that's all that counts.
In other words: this offer is not a dollars-and-cents offer, it is a peace of mind offer, with a dollar figure that is bad but not ludicrous. There will be some owners for whom that's worth doing. Probably few if any DISers. But, as I've said many times, the DIS DVC frequent fliers are not at all representative of the typical owner.
And, at the risk of repeating myself: the fact that this offer is (or appears to be) targeted to people who are not using their points suggests that it is also a defensive maneuver against the Postcard Companies. You might not think a DVC owner would fall for that, but I've seen DVC listings on some of the PCC resellers, so it happens.