I agree with the above post wholeheartedly I suck at the games though. The only one I've ever beaten on normal(without lame exploits) is 9. 9 doesn't really even count.
Touhou sucks. Nah, just kidding. I just don't find its games and music interesting at all. I hear its music on Akihabara a lot. In Japan, it's for otakus in general. My friends like it a lot and most of them are geeks.
You don't have to be Japanese to enjoy something foreign. And bland? I don't think they aren't. Probably one of the most well-though out compositions of music ever rather than a boring-*** generic rock song.
*didn't bother to google* In all seriousness, Touhou is really popular here. 80% of my Japanese friends are geeks and they all know or like Touhou. But, I was never a big fan of it. Even the game didn't look interesting.