There's just something about proper Disney Adults that I find nauseating. I've met a few of them, and the one I currently work with drives the entire department insane with it.
She's 37, morbidly obese because she likes to (and I quote) "eat cute Disney girl food!" (Processed crap), in her child's Disney lunchbox(es). She wears Minny Mouse ears and headbands to work. She dresses her two handbag dogs up in Disney outfits for babies. Her entire desk flickers because of the lights. She's single and still lives with her parents, her entire room is a Disney museum. It is ALL she talks about and I've seen her break down and cry when she couldn't buy the Disney merchandise she wanted.
That's a Disney Adult.
People watching the movies doesn't bother me. I still get a nostalgic lump in my throat when I watch Beauty and the Beast, but that's the extent of it. I find Disney a bit sickly, it isn't just childish it's saccharine sweet and (as another poster said) unsophisticated in its execution. The animation isn't actually that good in comparison to actual adult animation. The songs make me cringe.
Happy for my kids to watch, and I'll buy them the odd Disney toy here and there, but quite frankly even for children there are better stories and movies out there.
I'm not a big Harry Potter fan now, but I can see why people still like it. The adults now still into the fandom usually read fanfic which centres around the characters as adults (and lots is better written than the poor drivel churned out by JK.) . I've no problem with them dressing up, cosplay is cool. Halloween parties are great.
Disney, on the other hand, centres around child-like qualities. I understand escapism but it just makes me cringe for the most part.