And even the one thing that might, to a degree, be considered better- community- was a result of having a small community with no cross realm. Do we even know classic will have no cross realm? Even if it did- you ultimately ended up doing the exact same thing- standing around in one place spamming chat for a group instead of using a group finder- however, in classic you had to stay in the city due to how chat worked, whereas group finders made it so you could do things while waiting. Vanilla was actually the worst when it came to forcing everyone into the same place- IF, SW and Org were always absolutely packed.
There's nothing wrong with enjoying Vanilla WoW, but please don't try to make it out as something it wasn't. The rotations in this game's easiest to play class are ten times more complex than anything in Vanilla. The boss mechanics even of Naxx fights were more simplistic than even some levelling bosses in this game- sure, getting 40 people to do the safety dance when graphically it barely even showed for many players, there was lag, and there were no indicators was 'difficult'- but I don't think it's a less 'braindead' encounter when most of the challenge is lag, 39 other players doing it right, limited space (C'thun eye beams comes to mind), and not actually knowing when or where attacks will land.
I actually think it takes far more effort to learn fights based off having to observe rather than having to memorize a strategy and stand in the correct spot.
Also- 15 year old product more appealing than the current version? It'll have some popularity, it'll definitely spike at first since people will be done Azshara's initial push when Classic comes out, and no doubt many players will spend time there between major patches. But I think we need to wait a year before we can truly say it's more appealing.
There were things I enjoyed about Vanilla, don't get me wrong- I had more fun with pvp matches that had substance and the long AV, and I liked the feeling of growth through the dungeons, as well as the value of CC and non-rotation abilities since they could actually work on mobs in dungeons. But- it was not a complicated game, it was not an intelligent game, it didn't have hard mechanics, and for anyone to ever complain about 'waiting' in a modern game and then try to pass off classic wow as BETTER makes my first thought be 'this is a person who has never played vanilla wow'.
Vanilla WoW is the game of waiting- you wait for buffs, you wait for your party to get there, you wait for resources to regen, you wait on excruciatingly slow flight paths, you wait to get a party to begin with, you wait for bosses to respawn on wipes, you run through massive dungeons and zones after wipes. You wait wait wait wait wait- half the game was waiting or travelling.