I had an experience at a quilt guild that should happen to no one..
i purchased many unopened boxes of fabric at an estate sale. When i got them home i discovered thousands of pieces of poly knit squares. I decided to turn them into charity quilts and displayed many at "show n tell". As i was leaving the meeting, a remark was loudly made behind me " you're not a REAL quilter unless you use 100% cotton". This was about the fifth time her snide remarks had been simed at me and i was fed up...
my response was" well, in my opinion you are not a REAL quilter until you can quilt with fabric that stretches in every direction and make the seams match!"
oddly that was the last of those remarks, as she purchased all her quilts as finished tops!
Sometimes you just need to shut thise folks down!