Because they aren't based on a tween book that was popular for a total of 15 years? Because they've been mainstays of the most popular theme park in the world for 30 years?
Besides, that was my response when the PP asked if there were 20 year old rides that draw people to WDW...and those were the responses off of the top of my head? Had nothing to do with comparing them to Universal.
I'm not saying Potter-world/Ville/Land isn't the Bee's knees. But everyone points to that is an example of "how much better Universal is doing in Disney at everything." My original point was, and remains, that Harry Potter, the phenomenon, will evaporate as being such a big deal. Right now it is a very big deal, because there is a huge age group that grew up with the Potter books and movies. Those people get older and their children will probably not have the same fascination. Therefore as someone said before, Universal will have the option in 20 years of tearing the whole thing down and putting something new there. But Disney doesn't have to do that. Their rides have staying power as evidenced by the several I listed earlier that are still favorites and have been there for 30 years.