You know why you don't see other roms complaining about /having/ an app drawer? They have the option to go without that doesn't change the interface of their ROM.
And that's the main thing, when you break it all down. People like to have the option available, even if they're not going to take advantage of it; Android is effectively /built/ on that premise.
As an alternate view to folders, I personally feel that folders hinder my process so I instead minimise the amount of folders I use, effectively breaking it down to games, and apps. I don't categorise the apps in my head, when I wish to search for them, I instead simply know the name of what I'm searching for. Needing to remember that Facebook is in my social folder goes against my immediate instincts to simply look for Facebook. That's where the app drawer excels, in its simplicity.
I'm otherwise in complete agreeance that unnecessary additions are counter-productive... but that's only true of an app drawer if you're going out of your way to implement the extras.
MIUI is far superior in overall design than other ROMS available, at least in personal opinion, and the lack or addition of an app drawer wouldn't change my mind either way. No one is unhappy using MIUI, who still uses, and no one is so unhappy without an app drawer that they're crying themselves to sleep each night. OPTIONAL functionality doesn't affect anyway, and is effectively what is being asked for.
No one is pushing anything down your throats.
[/devils advocate]