Let's not mix Emos with Goths. They are not the same thing although to the untrained eye they look similar.

Emos as Gok said is a communal glorification of depression. They like getting together with others who feel the same way because naturally, missery likes company. These people refuse to better themselves and just dwell on how everything sucks.

Goths on the other hand are something entirely different. I will quote from wikipedia as my explanation could be a bit clumsy:

The goth subculture has associated tastes in music, aesthetics, and fashion, whether or not all individuals who share those tastes are in fact members of the goth subculture. Gothic music encompasses a number of different styles. Common to all is a tendency towards a lugubrious, mystical sound and outlook. Styles of dress within the subculture range from deathrock, punk, androgynous, medieval, some Renaissance and Victorian style clothes, or combinations of the above, most often with black attire, makeup and hair.
The awful thing is that in recent times the everyday community has begun to mix Goths and Emos into the same subculture when they are entirely different things.

I can respect a Goth but I can't a self destructive Emo.