'Your taste in music is crap.'
I hate it when someone says this to someone for loads of reasons. For one thing, most people will have a different taste in music from you so your opinion on music is subjective. Just because you don't personally like that kind of music doesn't mean it isn't good.
Secondly, if a certain singer or band makes someone happy, don't make them feel bad for listening to that person. Personally, One Direction's music always lifts my mood so I have a lot of their music on my playlist, but people usually take the piss when I tell them that.
Lastly, how does someone's taste in music effect you in anyway? Just let people be happy!
Rant over... For now.