Well, outside of roleplaying, there are the Grand Companies and starting quests, which others may want to experience.

I guess it doesn't help that I always have a terrible case of alt-itis. Unless it's Aion or Rift. >.>

EDIT: I do agree with a lot of what you said, so don't think I'm disagreeing with everything. I'm just bringing up a reason a non-roleplayer may want to roll an alt.