I haven't given up dancing, but I rarely go out anymore. I am a timba fan and the timba nights have gotten all watered down with bachata and kizomba an reggaeton. I'm not interetsed in that. So I mainly go out when there arre Cuban concerts. Then there is usually a Cuban DJ and other music is relegated to a different room.
We just had a Cuban festival here in Stockholm last weekend and it was really fun to reconnect with the people I haven't seen for years. If I could find a good cuban night here I'd start going out again.
As for why other people quit: a lot of my friends who were single when they started dancing have since gotten a partner and had kids and just don't have the free time that they used to.