Let's be clear - there's no 'gator problem' at Disney. There are gators ALL over Florida (Well over 1 million is the last estimate I saw) - if you see a body of fresh water, it's a good bet to assume there is one gator in there. Heck, they even find their way into people's pools from time to time.
Disney has been one of the best when it comes to managing gator population on their land - they have a great program in place with full time employees who's jobs it is to locate and relocate any problem animals. They also don't relocate -all- the gators - they are necessary to keep other pest species under control, as well.
This was an awful incident, but not a common one. I believe this is the first time anything like this has happened since WDW opened 45 years ago. I'd hardly call that a 'problem'. Independent wildlife experts have weighed in that if it was an adult standing there, the gator would not have gone after them. The child was, sadly, the right size to be easy prey - if you've seen some of the small deer-like animals on property, which are common prey for the gators, the size is very similar.
Gators are opportunistic hunters - they are extremely smart, but they don't stalk prey the same way that big cats do, for example. The gator saw an opportunity and took it. It was a tragic event - but there is no more blame on the gator than on the parents than on Disney.