I believe most MWSD clubs these days are a lot more open. My experiences -- limited to dances in NYC and Somerset NJ -- is that everyone is welcome. I've also been impressed by the people I know who do contra and MWSD and I know how much many of them value their friendships through the clubs. I suspect that bad experiences these days are either outliers or the result of individuals behaving badly (though it sounds like, in original post) organizers were abetting the behavior.
Anyway -- my contribution here is just to say that I think anyone dipping a toe in MWSD is NOT likely to be met by some of the unfortunate kinds of experience folks have had in the past.
Ridge