If I want to play 20 hours of FFXIV a week, and happen to only like one particular job - or simply have some reason to want to level that one to the exclusion of others - I don't think it's unreasonable that I get to do so without arbitrary and ill-conceived barriers like this on it, and I'm not sure it warrants being told that I need to get a life WoW has a far better system if you want to encourage different jobs or to help people who play less to keep up.

In short, it's stupid in a great many ways to penalize the people who most like what you're selling.