Can't criticize anyone.
At this point Riot has been harsher on inappropriate words in League. However it's moved to a point in where if you critique anyone's gameplay in game its a punishable offense. This goes beyond calling someone bad or improve this. Just simply telling a person they have made a mistake is punishable. I'm not sure on how Riot wants to fix this. Perhaps in the future Riot could implement a coaching feature. Where you add a friend and they can create highlights for mistakes and good decisions. IDK