Everyone has their own unique taste in music. Whether it's Metallica or Madonna, everyone usually knows what they like.
Music makes people happy, and it's a beautiful thing. However, a common problem I see within music discussions is shaming other people for what they like.
It doesn't happen all the time, but it is a recurring problem. Fans of different genres will be caught in wars about which music is better.
In all honesty, I find that fans of rock music tend to be the worst at music-shaming. As a rock fan myself, I think it's totally rude to make someone feel bad for liking what they like. Sure, it might be awful music, but if it makes them happy who cares? You're not better than everyone else just because you listen to the Rolling Stones.
I'm not saying you need to pretend to like One Direction just to please your friend, but saying it's not "real music" and just making them feel like crap for enjoying something isn't being a great friend. We have no right to ruin other people's happiness.
All in all, I think certain people need to be more considerate of other people's enjoyment. I think it's important to understand the line between playful criticism and being a jerk. Let's all just try to be mindful of what we're saying to one another.