I don't hate it, I got 75 hours of entertainment out of it (according to Steam) before I got bored of it. Which, now that I think about it, makes it one of my most played games EVER.
Thing is I don't usually enjoy Multiplayer, but I happened to do quite well at MW2 (well, on some of the game-modes anyway) and there was a distinct enjoyment out of beating all those whiny 14-year-old FPS players that I hate. I got accused of hacking constantly, and it just made me smile evilly >
Also, one of my biggest problems with online FPS games is there is no sense of progression. You don't really achieve anything which makes things feel pointless. But MW2 provided me with a levelling system which I had not experienced before in an FPS game, granting me upgrades and weapons as I go, really giving me a sense of actual accomplishment. (Incidentally, I got bored of the game once I unlocked everything I wanted, and as a result haven't played it since)
I understand its flaws and I can see why people hate it. I also thought the single-player campaign (which I actually bought the game for) was mediocre, and I'm fucking sick of war games in general, I hated the setting and general over-the-top manly bravado that the series represents. Actually now that I say that, I forgot why I actually bought the bloody game in the first place - probably just because the COD4 campaign was pretty great. I also bought the PC version, so I had to put up with the horrible matchmaking system, lack of dedicated servers and minor framerate issues due to it being a pretty shit port. But I can't deny that the multiplayer is very addictive, and if the next game has the same kind of multiplayer system I can definately see myself buying it. I gotta be honest, for a game to keep me playing for
that long is something unprecedented in my case, so overall it was $100 well spent.