For one, in Quick matches, people that join and are in spectator mode should not get a win/loss on their record because they have yet to play in the game at all, it's roulette whether you actually get into a game that's about to end or one that's just starting. Normally I would say that's fine, but to give a loss to someone who joins with 1 life left on the team you're supposedly joining, gives a free loss to you. (Of course TDM is what I am referring to)
Second, and I know I'm going to get flamed by all the Sawed off noobs out there, but seriously having a gun like that in the game ruins the spirit of the game. That's my opinion, but I feel like it should be removed, it isn't fun to deal with any random idiot that can just stand around a corner and press the right trigger. Now trust me I've been playing this game series since '06 and I know how the game has changed, I remember the GoW 1 shotty, the thing was a nightmare, but it still required some skill to get more than one kill in a row. I feel like people use the Sawed off because they don't know how to play yet, and that's ok, but the majority of players that use the thing have little to no skill even later when they want to switch to the Gnasher, or god forbid one of the mid range weapons.
Third, and I know it's not just me, but I am sick and tired of all these hacking, modding p.o.s. people in the versus scene. It seems like every 12 year old kid with a USB cable can hack the crap out of the game, making it rough for people like me that use skill to play. I really don't care if they modded their medals to have them all onyx, but to mod versus stats and to have auto aim mods, I mean how is that fun? Honestly the Host system on GoW 2 was faulty sure, but when people hacked that game it wasn't impossible to kill them, now people mod the Sawed off so they can AFK and when someone walks by their mods just auto aim them and they can press the RT and get free kills.
I don't know, maybe I'm just having bad luck, but I can say I am more skilled than the average player, and the above things just make it hard if not impossible for me to have a good time on the game, in versus at least.