”Why would anyone object to singers mentioning their own gigs on this forum? Promoting live events is one of its functions.”

Absolutely no objection at all if it’s done honestly, i.e. by the person doing it in their real name, not a pseudonym. Otherwise, to my way of thinking, it seems a seedy, dishonest way of promoting one’s gigs.

Although many of us here know who ‘The Sandman’ is in The Real World, a casual reader may well not have that kind of inside knowledge. That’s all.

As always, the standard disclaimer applies - IMHO. However, I realise that YMMV, and I’m cool with that.