Not surrendering to piss off teammates
I think that not surrendering, not because you think you can win, but because you are trying to piss off teammates should be a reportable option. I see this a lot in stompings. In my last game, our mid went 0-10. We were down about 17 kills with all lanes lost and a massively fed opponent. The teammate refused to surrender citing that he wanted to extend the misery of the games as the reason. We were at a 9k gold deficit, which ended up being 16k and it was over. This is definitely a negative attitude and depending on the way it is phrased, should be considered verbal abuse. Yet another abuse of the system.