Well, I guess somebody has to play the villian here.
I have been going to WDW since 93. Been a good, what, 20 times (at least). Single guy, say early 30s (not that that is accurate, but it makes ME feel better!). I am NOT, nor have I ever been, a major "Disney" nut. I have really only enjoyed the parks, and not even the thrill rides (I can't do those). For me,. I understand both those who love WDW, as well as those who simply see it as for the kids.
In many ways Disney has changed substantially since those earlier years. It used to be that going to Disney was stepping into another world. It was all about the imagination, and letting your imagination free again. But I see that it has changed. Now it's all about the Disney Characters. It's gotten to the point now that there are rides I simply don't "get", because not having kids I haven't watched all the new animated features. I don't know the story lines, so I can't relate to the rides. There was a time when in the MK, there were only two rides outside of FantasyLand that were at all based on Disney movies - Tom Sawyers Island and the Swiss Family Robinson's treehouse. Now everything is about the movie and the characters. It used to be that you could find quality merchandise and shopping was fun. Now it's just branded stuff.
I still have a sense of magic about the place, but only because I have learned how to do that. I often skip rides, and when I do them I am usually looking in the other direction. I have learned all the nice things there are outside the parks themselves. I have learned to ignore all the marketing hype and the sugar coating that makes you more uncomfortable and suspicious instead. I know how to avoid the herding and becoming the lowest common denominator.
I see adults go to Disney now, and they pretend to be kids again. They enjoy themselves and that is a good thing. And I am not trying to rain on anyone's parade about Disney not being fun. But when you do encounter someone who says "Disney is for Kids", instead of immediately trying to convince them that they are too serious, think instead of what perhaps THEY would be looking for in a vacation. Walt Disney World may very well offer their dream vacation, but if they keep being told that the way to enjoy WDW is to be childish, they aren't going to find it.