Not all emos cut themselves. Not all people who cut are emos. And people who DO cut do it to feel something, because they can't feel anything. Others do it to release pressure, to let that blood/pain come out. Some do it to feel better, as pain brings a good feeling after it stops or during.
Emo does not mean you cut yourself. Emo is a style of music. Emo is also short for emotional. It's human nature to be emotional. Therefore, everyone is emo. I'd do some research before you use words you obviously don't know the meaning of.
This question is offensive to any person who cuts or is emo. Emo is emotional, not necessarily cutting. And they cut for their own reasons. Is it right? No. But you shouldn't make such a generalization. People who cut, unless they are attention beggars, have depression and tend to not feel like they are worth much