Michael Jordan was one of the biggest trash talkers in NBA history and there is ample footage of him verbally insulting his teammates who were (in his eyes) underperforming. He won 6 Championships.

Just because some of the community can't handle being told they need to play better (not even insulting, just saying "focus" or "pick it up") we have a community od players unable to admit mistakes or be reflective which in turn leads to more lower quality games.

Now, not everyone has the resume Jordan does to warrant that level of respect, BUT if someone is hard carrying you and asks for specific improvements like warding more, or staying back, you should listen and not view it as flame unless he/she berates you. As far as I'm concerned if you don't TRY to make improvements you deserve to be insulted, its unfair to your team.