The term "Folk Club" has a broader meaning here in the New World. True, it does apply to the dirty, smoke-fill, back rooms of few comforts, many disappointments, and a few treasures of which you speak.
It also applies to the now-smoke-free cofee bars and/or nuveau-cuisine acoustic venues. It applies further to the many rich and wonderful 'Folk Music Clubs' throughout our countryside.
It was the Branford Folk Music Society that reintroduced me to folk music in 1988, the Houston Folk Music Society that added to my pleasure during the six months that I worked near Houston (1993), and the Tulsa Folk Music Society and the Oklahoma City Traditional Music Assn that sustain me today with wonderful opportunities to learn, play, sing, and share our music.
And there's the Wash DC area club that does great things like the Getaway.
Just another twist. Please excuse my tangental vector.