I have hard time to understand why this, I have some ideas like :
It make some economy, some trading.
But yes, in this game, one of the first thing I saw, the first time I played :
I can do everything with 1 character.
And yes, better the desynthesis, you could.
You can lvl all fighting/healing classes
You can lvl all crafting classes
You can also lvl all gathering classes
Some of them even share some piece of gear.
If you're hard-core, you can even get max gear on all of them (ok, not becoz of the limit of coil, et the limit of Poetics, but still, everyone -hat is playing since month- have at least 2 classes very well geared, some players even more)
But for Desynthesis, you can get only 3 lvl max, or high lvl (since low lvl is kinda useless...), why changing the main point of the game now ? I dont get it.
I want to get lvl 70-80+ on all desynthesis classes, specially for the items I cant trade to ask a friend to do it for me (if all items where tradable, this wouldn't be a problem)