I've known many people that have to have every Disney movie, even if it was not very good. But they aren't rabid in other Disney areas. I know some people who have Disneyland passes and go every week, but that's because, with a pass, it's a cheap date. Disneyland and WDW themselves have their own charm (and their own miserable commercial side). Collecting pictures of yourself (and your kids, if you must) with every Disney princess is not much different than collecting coins. IMO, where it gets weird is when your entire life revolves around it, and you HAVE to bring your whole family into it or get angry at them if they don't want to do it, and you have no other life besides it.
My kids like Disneyland for probably all the wrong reasons: How did they build this ride? How could it be made better? That robot looks just like the one I built (and it does!). Look, there's a place where the characters disappear into the tunnel. If I take the distance this ride travels, then make the 30 degree turn, that drop down puts us three feet from where we were just waiting, on the other side of that wall. Canoes! This Dumbo hedge is built on chicken wire, I think I could do that. That kind of thing.