From what I personally experience, I level a class because I enjoy it. FFXIV punishes you for enjoying a class too much while leveling. There's really no other way to look at it. The system's for limiting progression, not to help with 'branching out'. The 'freedom' of the system is just that; an illusion. The subjob system from XI had infinitely more freedom without any of the halted advancement. If someone wants to try out another class they'll do so because they enjoy it. Forcing players to advance out because there's nothing else to do when they hit this arbitrary wall is ****-poor design. I seriously would have rather they just put in a low level cap and increase every 2 weeks. It would solve the design issues and give them time to develop content without punishing players.
were that guy in FFXI who only had a main job and no /sub - how did finding parties go for you? :P
Seriously, if you didn't level a /sub noone wanted you in a party and since FFXI was a very "group" based MMO you didn't advance. Depending on your class anyhow. BST could do it, but again with no /sub you would be gimped.
In FFXIV you do not need to level a "/sub" to get to end game, in XI you did. In both games you bring more variety to what your "main" class can do, however unlike XI - if you do not level any other class it will not be game breaking
I do understand the fact that you are limited by how much you can level in any given week, but really from what I have heard the levels are pretty high.. people in mid-20's/30's after 1 week?
That is my thoughts on it anyhow.