I'm a pretty big hipster when it comes to music. I listen to a lot of stuff that isn't very well known, or at the very least isn't "main stream." Justin Bieber, Katy Perry, Taylor Swift, those artists produce songs/videos that typically have hundreds of millions of views on youtube. The music I mostly listen to has less than 20 million, often less than one million. I listen to it because I like it, it's the type of music I like. Most of the stuff I listen to is more than just a pretty face singing dumb lyrics to a generic beat (what most pop music is). It's more intricate, more artistic, has more meaning, etc. You have to care a bit more and have a more sensitive ear to appreciate a lot of it.
I totally agree that most obscure music is crap. That's what sucks. For every gem I find, I come across 20 or more songs that are utter crap.
Also, I don't seek out obscure music to be cool at all, nor do I stop liking a band or artist if it becomes popular. I just look for music that I enjoy. I like to share the music I find with others because it's like sharing a rare dish with someone. It takes effort to find cool obscure music. Part of the reward of finding it is sharing it with other people who enjoy it.
I do still listen to and enjoy a lot of pop music, but it's not my favorite genre.