Griefer teammates

Wanna know what happened in my last game? My teammate told me to throw a molotov down Tunnels. And then he and his mate jumped into it and let themselves die, saying "Enjoy your ban dude" over his mike. I was very confused but people are generally trolls on here anyway so I didn't think too much of it. On the next round someone said "All 5 of us throw decoys at our feet then we'll go long." I thought that'd be pretty funny so why not. He stood on my decoy, had his mate shoot him down to his last shred of health, and then died. Yet again saying, "Enjoy your ban dude."

I was given a 30 minute ban and a de-rank. I don't understand this community, and I sure as hell don't understand how this can be okay with the game's kick systems. Anyone else seen people doing this recently? This is the first I've heard of it.