I personally love having the ability to level multiple classes/jobs on one character. I just feel more attached to my character, experiencing everything from their point of view. Also I find that people recognize me as my character, and i recognize them as such too, I've even called a rl friend of mine by his characters name in public...

I doubt I could stomach this game if I had to roll alts, that's one thing I hated about nearly all other mmo's. I hate that feeling of being pigeonholed, I'll choose to specialize in whatever role I want to specialize in, but I like to play around with the other jobs as well. Plus if we could only level one job/class per char, there would be no cross class abilities for us to utilize...