You don't have to be positive to avoid punishments. You only have to refrain from being negative.
I'm one of the most cynical, jaded, anti-politically correct people you'd ever meet in real life, but in game I just shut my mouth and play.
preach it
I wish I was more like you...
I've personally found that when I play, if I get angry at something giving a tip to the allied champion is more useful than degrading them. I can internally be yelling my heart out, but telling them something constructive helps a lot more throughout the match.
