I try to be open to all styles of music, but some styles I find difficult to enjoy overall. Even then, though, I'll still pick out parts of a song that I like. An extreme example: Simple Plan are the lamest band on earth in my opinion - typical pop-punk garbage combined with incredibly whiny vocals - but I can enjoy for example the guitar riff at the start of their song "Me Against The World" before the vocals come in. That's an example.
But the thing is I'm not going to discriminate on people based on music taste. It just so happens that I get along better with people who have a similar music taste because I'm a boring person and the majority of what I talk about is music, so it's not intentional that I make friends with people who have what I would consider a better music taste than the average person.
I try to find good things with every genre. Country music for instance may have a good guitar part while the over-American-accented vocals ruin it for me, or NWA might have a pretty cool beat in their songs but the constant swearing and lack of lyrics I can relate to ruin it for me. Of course, there are some things I can't see any good in, but I try my best.
Case study: it's irritating when some of my indie-listening friends criticise me for listening to AC/DC. For those not in the know, AC/DC has had two main vocalists - Bon Scott who played their earlier stuff (Jailbreak, Highway to Hell etc.) and Brian Johnson, who took over after Bon Scott died (basically everything after 1980) - and what most people hear is Brian Johnson-era stuff, which I personally don't like. People who generalise with music, in this case the indie friends, don't even bother to try and listen to the music in order to make an informed decision, or in this case listen to the Bon Scott era and see the difference between vocalists.