The game is designed around the 1 character for everything concept. It was designed to remove the need for alts which most mmos force on people.

All classes/Jobs can be played by everyone, All specs are for each class individually (They can be reset in a future version after certain duration of time), There are not rival factions (you can play with everyone), the mainstory line merges so everyone ends up with the same story. There really is very little reason for an alt. And if you want one you end up paying what you would on another mmo per month.

I can see this being a negative for Role Players who want different races, but for the average mmo gamer... really it is a plus to not have to use an alt.