“Who does this without posting signs”
=
If you need signs to stay safe and/or to not do stupid stuff your life is going to be just chock-full of woe.
I've lived in Florida for more than 20 years and see tourists come here all the time who don't fully grasp the risk that gators pose, especially when they've been fed by humans that should know better. We were the same when we moved here. No longer.
When a child was almost snatched by a gator on this same beach a week before this two-year-old boy was killed, the Disney company absolutely should have done something, like warning guests when they checked in or actually placing signs on the beach that mentioned alligators - not just "no swimming" (every body of fresh water in a Florida park has signs near the water warning of the dangers of gators). They did nothing. The chairs stayed on the beach. The movies continued to play, and their employees continued to feed the gators (against the law in Florida).
Blaming the parents solely for this tragic event requires the total disregard for the facts and a strong does of shallowness.