If you pay to hear a particular group/singer that's one thing. Between you and them. Attending an existing club is quite another. I'm with Folkiedave -- choose a different place to hear your favourite performers.
A club runs itself for itself. It has the right to do that any way it wishes, including asking for payment. Nobody is forced to attend.
I have also played all types of music. I set myself high standards but I don't impose my tastes or standards on others. I choose the places I attend carefully. If our way dies with us old folkies -- well that's sad for us -- but we have the right to be the way we are.

Thing is -- here I go getting all cranky -- We were once young. We remember it well. Young people were never old. You can't possibly understand old.
Cheers, cranky old Joy