For me I think it's because music is a hobby I care a lot about, and I'd like the "option but not the obligation" to easily improve my experience. I've tried a bunch of other music players over the years (on the go, Plexamp seems the most promising in the "access and play all the weird formats in my music collection anywhere in the world, look nice, and get out of my way" category) but I keep coming back to foobar2000 for the sheer capability and flexibility to tweak how I manage and interact with my music every day.