Several movie and TV sites have come and go where you can just visit and watch without even creating an account. Quality might not be as good as a paid service and they are no doubt in the grey-to-red zone legally. I don’t see the same service for music.
Why do you think is there such a difference in trends?
I love Pirate Bay and torrents, but there’s barely any music there. The rare time I find something there, it has 0 seeds.
Soulseek, on the orher hand…