I met many people who just screw up the game all along in Competitive Matchmaking. They just damage their team but don't kill so they don't get banned, and if you try to kick them they get out of the game with no penalty and the game is pretty much ended because there is almost surely someone who votes no to continue with bots. There are also games where the people shout at you for every little mistake and try to kick you for them. Also, someone team damaging me (he started first, and did it even after I stopped) and then voted to kick me. CS has a nice community.