I have been trying to sort through this thread. If I dump the crap
there are valid discussion points left.
Open mike's can be a lot of fun. Those who go do so of their own free will. I would suggest that if you don't like the performance or the venue that you do not return. Unless criticism of a performance is constructive with an attempt to help it is best left unspoken. Over the years I have watched many performers who "sucked" on their first attempt
improve to a remarkable degree as they gained confidence and skill. I am sure that someone discouraging them when they are so vulnerable, would be considered an "AH" by most caring people. If the intention was to belittle the performer they only belittle themselves.
Some are by nature, more skilled and gifted than others, but there is nobody who will not improve as they gain confidence. The best way to help is to show some appriciation and encouragement.
As for judging people because they only use 3 chords and a capo to do a song , these were the tools of Woody Guthrie and Hank Williams.
I have heard Woody quoted: " Anyone using more than # chords is just showing off!"
Hank had a great back up band called the Drifting Cowboys. On some recording sessions they wanted Hank to leave his guitar out but in most cases he refused. My favourite songs of his were the demos that were released after he died . Just Hank and the guitar and in most cases three chords with the odd minor or seventh.
                           Sandy