If you want to see horridly bad multiplayer maps, then look no further than Brick Force!
There are far too many "XP grind" or "Free XP" maps, (as in more than zero). They consist of nothing but a 15x15 box, which everyone spawns inside.
It gets worse. There's the ones that are 15x15 boxes where one team spawns inside, and the other team spawns outside with all the turrets and gets to mow down the helpless other team.
Yeah, I'm not your personal XP dispenser, @$$holes!
Oh, and lets not forget all the wondrous creativity found in the recreated CoD maps... *sigh*.
Not all user created content is good. In fact, most suck.