Awwww! *pets* I don't think it's because John's dad is a jerk, but rather he's just kind of cheap. It makes sense, if he was born in the late 30s, when he would have grown up with the Great Depression and the war and spent the first years of his life watching his mom going to work and clipping ration coupons. So he'd kind of see family vacations as inherently cool and already indulgent things (which is why they go to old battlefields instead of cool places like Disneyworld, where all John's friends are going).

Though if you're going to drag your kids all the way down to the Everglades, the least you can do is let them go on a hydrofoil ride through the swamp and hold a baby alligator. It's the only real reason why you'd go, because even though the Everglades are a fascinating (and currently gravely endangered) ecosystem, they're kind of boring.