Everybody is digging the music, but no one is dancing.
That's usually a "DJ trying to be too cool" problem.
There are automated DJ programs, but so far, no one seems to have one that takes in video of the dance floor, tracks how many people are dancing, and adjusts the playlist accordingly. I thought of doing that 20 years ago, but now it would be both feasible and cost-effective. (Optional feature: also connects to the bar cash register system to optimize for revenue.)