A lot of you are saying that in 4E, you are unable to ... how do you put it? ... roleplay the way you want? Play the way you want? Experience the game the way you want?
As a DM and a player, 4Ed has me feeling handcuffed.
For me, it boils down to these major things:
1) The 4Ed rules- particularly the multiclassing rules- don't support the way I've been designing my D&D PCs for 30 years. As a player, this vexes me greatly- my taste has been voided by game mechanics.
2) Some of the changes to crunch and fluff seem arbitrary to me, and are not obviously an improvement over their counterparts in previous editions.
3) Some of the rules changes treat the player or DM like an idiot, or are utterly nonsensical. I'm not talking about the rules that simplify or streamline mechanics. I'm talking about things like the magic adjustment charts for monsters and NPCs. If I, as DM, give an opponent a +3 weapon, I mean for it to give that foe a +3 bonus, not something adjusted down because the creature is particularly powerful. If I wanted to give that foe a lesser bonus than +3, I would have done so.
4) Some of the rules I'd like to use as a DM (since I've been using them for 25+ years) are simply absent, like rules for creating unique magic items.
5) 4E is not backwards compatible. I play in several campaigns, one of which has lasted 10+ years, another which has lasted 20+ years. Because of the rules changes, some PCs are simply not creatable, meaning that to update those games to 4Ed would require retconning or waiting until some future date uncertain for a product which may never come. Understandably, I and the other players aren't too keen on ditching established campaigns merely to jump into the new system, especially with its known warts and all.