I disagree with that heavily. A lot of the times when I screw up (and everyone will screw up eventually) I know I did something wrong almost right away. Usually because I get caught and die for nothing shortly afterwards. And I beat myself up over that, I say "Come on Krossy, that was stupid, learn from that mistake and don't do it again". This all takes place about half a second after I make the mistake, so by the time the grey screen rolls around, I've made peace with my actions and moved on.
What I don't need is some wiseass on my team chiming in with such constructive criticism like:
"..."
"Why"
"WTF"
"lol"
/all "this guy"
That's not helping me, that's not helping you, that's not helping anyone. Except the other team, since I may be tempted to mute the wiseass afterwards and cut down on non-ping communication.
Long story short, don't bust the balls of your teammates. It hurts more than it helps a lot of the time.