How to properly criticize someone:
1.) Pinpoint the area of fault. And no, you DO NOT assume someone's character based on that fault.
2.) Assess the effects of that area of fault. How did it affect you and how WILL it affect others?
3.) STOP BEING AN ASS I SWEAR TO FUCKING GOD

4.) Talk it out. Grab their perspective EVEN IF it seems pointless. You do not have to say their perspective is pointless because this triggers the ego that you all so claim to hate so much.
5.) Approach by claiming to understand their perspective FOLLOWED BY why you object it

6.) Give real life examples of how that area of fault will affect others. MAKE THEM QUESTION THEIR ACTIONS INSTEAD OF ACTIVATING THEIR EMOTIONAL DEFENSE MECHANISMS. I swear there's no other person to blame for them being defensive EXCEPT YOU.
7.) Be fucking civil. DISCUSS.

8.) Once everything's been settled, it will take time for a new behavior. You do not antagonize them in this stage that follows. Change does not happen overnight so please do not expect that antagonizing them will pressure them to do better because it only inhibits that behavior.

I mean unless you pretty much don't care about the person then lmfao go but don't expect to see good results and then end up mad again because you failed or chose not to take action.