Over the summer I was at the Blue Whale jam session when a handful of drunken girls were asked to leave for being too chatty. Set aside the miracle of a bunch of drunken girls actually being at a jazz club; the fact that they were booted on a night when literally anyone can play is absurd. And probably not too good for business, either.
Regardless of what snotty musicians might think, jazz clubs could use a few more noisy drunks, girls or otherwise, because not only do they pay the bills, they bring a bit of energy to a sometimes-sullen genre.
Before long jazz will be as bad as classical. The Los Angeles Philharmonic's website says that if you're not sure when to applaud, "the safest course is to wait until the conductor has turned around to face the audience and everyone is clapping." The message seems to be that people with unbridled enthusiasm should go somewhere else, somewhere where they're not as strict with the rules to their music.
But second only to classical snobs are jazz snobs. For a genre based largely on improvisation, it's odd that they take pride in applauding at just the right time , and pity those unfamiliar with the genre's increasingly rigid code of conduct.
Jazz got its start in brothels and bars. Somewhere around the time Miles turned his back on the audience and suburban kids started studying it in college, jazz transformed from entertainment to "art," and nowadays rarely looks back. Over-educated musicians expect silence and awe at their increasingly inaccessible sounds, whether it is deserved or not. The threat of a slurred heckle could do a lot to put that pretension aside.