Guess what? If I went into a jazz club and played Appalachian dulcimer solos all night, I'd probably be told I didn't fit in there. But then, I wouldn't ever consider doing such a thing. Why in world would someone want to play modern music in a place that puts on traditional music shows? And, having been told rightly enough that they weren't appropriate for the club, why would they complain about it?

If a club doesn't want you, go play somewhere else. And please don't try to make it about quality, power, publicity, money, fairness, "denying the importance of", or anything else other than the fact that people who book music get to book whatever they want. If you don't like it, start a club and decide what gets booked there.