There are some things you can do to stay safer when you travel to crowded areas, mainly just basic situational awareness. Always be aware of the nearest exit, available cover, think of what you'd do in an emergency, etc. I think in terms of the three options: run, hide, confront - in that order of preference. Exit the situation if it's safe to do so, hide if it's not, and confront the attacker if you have no other choice, preferably en masse. I'm 'wired' to be more cautious/paranoid, but I usually have these things in mind in vulnerable situations. If I had to flee, which way would I go? Where would I take shelter? What do I have around me that I could use to defend myself or stop the attack? I think of these things when I travel ANYwhere, not just within the US. Unfortunately, 'tourist spots' are an attractive target in any country, just because they are very high profile and have worldwide impact.
And yes, it's very sad that we have to think this way anymore.
But also, while there are always high-profile casualty events in the US, I would still say it's far more likely you would be struck by lightning, for instance, than have that happen to you. Way more likely to be in a car accident GOING to Disney Springs. Not that that would be much consolation, I imagine being struck by lightning isn't much fun either.
Disney has plainclothes undercover security in the parks, and I imagine they do at Disney Springs as well. It would be very, very bad for business if there was an incident like that, so they SHOULD have a vested interest in doing everything they can to prevent them.