Going to Disney is like going to a big city. Considering the numbers, people die there, people get born there, there are ex-cons and criminals there. Disney does a great job of making people feel as if they are in a safe little bubble, but life intrudes.
I think people believe a bit too much in the sense of perfect safety there, but really, you have to have the same sense of self protection that you would in a large city, at a concert or state fair or anywhere there is a lot of people.
This could easily have happened at an offsite pool (and probably does, every week, as sickening as that is). I give Disney credit that where there's a problem, they step in quickly and deal with it. That's all they can do.
Pervy guys are a fact of life for every woman, young or not so young. We can teach them to speak up and be assertive, because this sort of thing happens too much. When you're at a place with crowds, your chances of it happening increase accordingly.