Club dancing in part follows whatever is in the mainstream pop music culture of the time. Right now I also think a lot of it is based on hip hop dancing, because of the rise of hip-hop related music in the pop world. Back in the 80's, people danced differently, and the music was different (anyone remember "gatoring" to "Rock Lobster"???).
I don't know that "old people" find Latin "degrading." The first question is what is "old"? A good number of youths assume that older people are naturally prissier than themselves, but the truth is that the oldsters were young once, and nowadays some of us were young in the 60's (lots of hedonism) and 70's (disco and sex everywhere). So, seeing people dance around in skimpy costumes with lots of fake tan and waxed chests comes across to some older people as more "cheezy" than "degrading." I guess if someone came of age in the very conservative 50's, and never let go of that despite the revolutions in society in the 60's and 70's, then that sort of person might think Latin is degrading.
And of course, there are super conservative people of all ages that would go with the "degrading" reaction. Heck, there are some Christian religious sects that forbid dancing, and of course there was that "Footloose" movie in the 80's about the kids in Kansas or Iowa or some other flat grain-producing state who were not allowed to dance in their county.
The only time I really see a negative reaction from people in the general public about competitive Latin dancing is when the really young kids (like, younger than teenagers), especially the girls, dress up like they are 24 years old. People get weirded out about pre-pubescent kids dressing and acting out adult sexuality. There's a real issue with that surrounding kids in the "pagent" circuit, particularly a few years ago when this one 6-year-old-pagent queen was killed in Colorado. So adults in this country are sensitive to things like that when it comes to little kids.