Pretty much, though in most cases it's not the artists themselves kicking up a fuss about it. Many of them have no objections to their music being used in adult games. It's the large music libraries they sign up with for extra exposure that prohibit it... even if the artists themselves give you the green light!
The name "Epidemic" really suits them just right. I think of them and
yersinia pestis comes to mind...
In Drifty's case, it was actually a musician who initiated the DMCA claim... It turned out that she's a devout Christian and the song he used had been written by her for her wedding... where she also sang it to her now-husband. Then she saw it used in a "porn game"...
Awkward.
Custom music is an option, but it's super expensive. Caribdis shouldn't consider that until he buys himself a place like Luna's uncle has and goes on early retirement.