I've not see this yet, but I've only been around a short while. I do come across players who berate themselves when disappointed about their own poor play, but I've never had any of them berate MY poor play. :-)
I get that golf is a frustrating game, so it doesn't bother me when my opponent expresses frustration at their own poor play - if we're being honest, almost all of us have been there before.
What I have found interesting is the couple of old-timers (not necessarily in terms of real age, but in terms of having been playing WGT for a while) who have very bluntly accused me of cheating; evidently it's a "thing" for experienced players to open new accounts in order to play at lower levels, and they assume I am doing this. I don't take offense - actually, I take those accusations as a compliment - but I do laugh at it, since, as noted above, I'm not even very good at this game. Reminds of something Abraham Lincoln said when Stephen Douglas accused him of being dishonest: "If I were two-faced, would I be wearing this one?".