This is a funny thread. The Bluegrass Police, sometimes also known as the B Chord Mafia, can be a difficult group to harmonize with. I can't even count the times someone has heard my Guild DV4 and commented about it's amazing range and how much bass it has, but then followed up with "Too bad it's not a Martin". (Is that pickup hooked up to a little amp inside the guitar???) However, there's a few simple rules for dealing with these folks:
Hide their capos - you can give them back later unless they are really intolerant and you decide not to.
Play something so not-bluegrass that the old timers might think it's an original. Like a Prince song or something. If you can convert the old-timers the others will follow. Also, any typical jam circle will likely have a few other subversives attending. They will get the joke and play along. This will allow you to identify who your allies are so you can work together to form a plan to play a song in a key other than 'B'.
Number one rule: Fight fire with fire - simply play louder, like everyone in Bluegrass does if they dis-approve of something.
Hope this helps, and remember, Bill Monroe had an accordion player for a while.