I know what you mean, once you get past the unique graphics and humor it's really quite bad. All the classes are specially tailored to destroy other classes. It makes the game balanced, but just a glorified rock paper scissors. I also hated that you have to unlock the better weapons and hats that boost stats, giving veterans a large advantage over new players. I didn't like but could tolerate it in CoD because there it was simple to do. Everything but moving, dying, and missing got you closer to the new guns, but in TF2 you need to get the achievements which make it much more specific what you have to do to get them and therefore far more difficult, made even moreso when all my enemies have superior guns to me. This really doesn't encourage a good community I imagine which I already found to be god awful. No body ever seems to work together and everyone seems to be a dick. Here's two of the best examples of this problem I can remember.
Example one: As a medic, countless seriously wounded allies ran right past me without giving me time to heal them and without waiting for our other allies, right into the room guarded by three fully upgraded sentry guns. Then they complain that I didn't heal them.
example two: As a demoman I was the only one guarding the breifcase when a lone scout infiltrated the base. After spotting him and being unable to kill him (he just shot the sticky bombs and you can't hit them with the grenade launcher, remember rock paper scissors) I immediately called for backup, and tried to hold him at bay using an ammo dispenser an engineer left. I waited ten minutes for my fucking retard teamates to finally show up and kill him. Ten fucking minutes before my team apperently remembered that the briefcase determines who wins, not kills and finally did something. What the fuck was so important that they couldn't spare one or two guys to defend the most important thing in the game?
Last, while admittedly a minor complaint I don't like losing all your weapons when you lose and are made a defenseless target for the enemy. The other players are alreeady the same retarded, homophobic, twelve year olds every body complains about lurking in CoD,but now the game itself is insulting me for giving it a chance.