how do you define bad musical taste?

You're right that it was hard to find. I think I was the first kid at school to get anywhere beyond chart music, and that needed a total leap into the dark - the Chart Show's Indie Chart with its lovely psychedelic carousel was about the only gateway I can remember. The first few NMEs I got were like discovering the Americas - Indie No.1s! Stiff Records! The Greatest Drummers Of All Time! - there was so much undreamt-of stuff to care about that I managed to miss Nirvana breaking about six months later because I was poking about in Sarah Records or some other blind alley instead.

For all that I criticise the greyness of indie as an aesthetic, I guess it really did feel like a world of discovery at the time. It was really weird to get to university three or four years later and find that, the odd metalhead or goth apart, people there had never even attempted a similar journey and were mostly content with stuff like Mike & The Mechanics.

first thing that came to mind when I saw the thread title was, "someone who doesn't like black sabbath."

I'd say if you enjoy the musical stylings of Nickleback then you are beyond hope.

I don't think it's so much the things you like but why you like them and how you express this liking
e.g.
National Review's Top 50 Conservative Rock Songs

though certain acts lend themselves to and encourage being appreciated in an ugly way (ha! nickleback!)

do you people pay attention??