i always try to be encouraging to other performers even if not apparently much good;thats how i started!
but if a muso badmouths other participants i regard their act negatively,even if they are brilliant.
it was,nt till i started writing songs that i took singing lessons and its taken/taking years of effort attaining the [hopefully]status of a singer.
maybe its harder for those already gifted[or think they are!]to be gracious to beginners and strugglers.
here in the UK open mics are generally free,other than buying a drink so there,s not too much pressure for performers and little to lose for audience