I am a former manager of a LQS and you are right, there is an attitude of snobbiness. Even as a manager I had to reject some fabrics because they were not to "our stardards".
I believe that fabrics have a trickle down system. New fabrics that are shown at Quilt Market by vendors are first sold to LQS, overstock is then sold to chains, JoAnns, Warmat etc. That does not mean that the fabrics are inferior they are just a little dated.
You can get the same battings, muslins, basics at JoAnns that you get at the LQS and at a better price..