I don't think courage comes into it really. I mean, what's going to happen to a labelless GUEST, if they adopt a label? All right, maybe if you are identified as being the person who uttered some opinion about some controversial subject, that might carry over into the music threads.

"That bastard thinks that euros are good/bad/interesting - so I'm going to sneer at what he or she says about banjo tuning."

Doesn't seem likely. And in any case it's easy enough using a different pseudonym for different threads, and maintain an unsullied anonymity, while exercising a modicum of courtesy towards others.

No, the only reason I am able to envisage for the practice (leaving aside the occasional time it happens accidentally) is because it's a way of blowing a raspberry at the rest of the Mudcat.