I agree with some of your points.
but,[Before I took up folk music I sang with a pop covers band. Yes, you may laugh (justifiably so) at this kind of outfit, but I've never seen a band of this type stop halfway through "Dancing Queen" and ask the audience how the next verse goes.]
a few facts,Elvis Presley forgot the words to: are you lonesome tonight,the Beatles were frequently out of tune,when they played in Hamburg, as were The Rolling Stones on occasions in their early days,the Dave Clark Five,had a drummer who[well the less said the better],many pop groups of the sixties could not be heard live,because of the screaming[and a good job too].
many of the pop covers bands are playing crap[just my opinion].
I would rather hear folk music performed not very well,than a professional competent pop covers band.
however, I think there is room for improvement,and some floorsingers,could do with more rehearsal,before performing in public,there are also some very good floorsingers[some of them do gigs and support their local folk club by doing floor spots Gary and Vera Aspey spring to mind
http://www.dickmiles.com .