Interestimg thread. I'd assumed it started with home theatre then spread to music.
I agree that a lot of electronic, music, which is what most of my collection consists of, has a lot going on in the sub-bass region, and even music that doesn't apparently have a lot of sub-bass might still have some, and this makes a difference. I think modern production techniques/trends often are far bassier than kusic in the past, particularly pop, so the influences of electronic music are felt through a wider range of music.
While I know I can't hear bass below 20hz, I sure can feel it, and it feels good. Having just added a small sub to 2 smaller speakers, I think I get better, and certainly deeper bass than would be possible without paying considerably more. It does give me a bit more flexibility with layout, and although faffing with the crossover, etc. could be annoying, I actually find it helps me dip the bass right in the frequency band that I was having problems with in my living room.
As someone else mentioned, I can turn the sub off late at night, and because I'm a tweaker at heart, I can even adjust the bass depending on the music I'm listening to.