Most after game speeches and those in the game are a waste of time anyway. They seem to me to be pointless as I know exactly what is going to be said. The stock standard 5 to 6 responses are so old hat.
And if you are the opposition do you really want the team that beat you to say the same old 'Thanks for the game, you played well, it was a tough game' etc etc. It doesn't mean anything. Socialising with the opposition later on is much better.
That's why Cruden's after match comment calling out the TMO for disallowing Nanae-Williams' try was refreshing. But he did say he was leaving so that's why he commented.
There are plenty of comments made through gritted teeth where the subtext is obvious for all but the most unobservant to see.