Sorry, but I don't believe any sane audience member "walked out of a gig" without hearing the band, because there were music stands on stage.
It might make a good story, but I just don't believe it.
As is being said, the band can be good, bad, professional or a bunch of amateurs, but there are far better ways of judging that band than their use of stands.
Anyone who hates a band without hearing them isn't someone whose judgement I'll take seriously.