The ANU Bar Finale Facebook page was asked why no "women or non-binary" performers had been considered.

The organiser of the gig, Greenrooms Canberra owner Garry Peadon's response drew ire.

"Why do I have [to] even think about this shit? What the f--- is a non binary?" Mr Peadon said on Facebook.

The comments caused headline act Regurgitator and Canberra band Slow Turismo to withdraw from the event on Tuesday.

Slow Turismo bassist Louis Montgomery said the gig had started to represent something they didn't want to be a part of.

"This felt like the best course of action for us," Montgomery said.

"I think the way the promoter reacted was certainly inappropriate."

Montgomery said the band felt an opportunity had been missed to educate the promoter and others on gender issues.

Mr Peadon said it was a storm in a teacup and didn't think the all-male lineup was an issue.

"I don't really know what's happening. I put together a gig of bands that I like ,and you know, have certain history with the ANU Bar," Mr Peadon said.

"This whole thing has been blown out of proportion, since when do you now book a show based on gender?"

Mr Peadon said he had tried to book female bands, but none had been able to perform.

A spokesperson for ANU Bar said there had been an extensive period for local bands to participate and selection wasn't prejudiced.

"What they do with their bands is up to the booker and the promoter," the spokesperson said.

In a post to the event, Mr Peadon said there were "no hard feelings" for Slow Turismo and Regurgitator's withdrawals. He said he had authorised refunds for those disappointed in the lineup changes.

In a statement Regurgitator said they'd withdrawn based on the organiser's response to criticism of the gender bias.

"Music is not about gender but we can not ignore gender in regard to the ongoing practices of music as an industry," the statement said.