i guess it's all a matter of what one knows. for example: the people you overheard didn't know where they were, or what they were doing. you, on the other hand, didn't know that ending a sentence (or two) with a preposition is unacceptable grammar...or; maybe you just forgot, as perhaps, was done on the occasions you mentioned.
the point is- give people a break. not everyone is obsessed over disney world to the point that we all are. perhaps they just don't care about these things; or, they are at wdw for the first time and are learning....just like you once did.