As an XI player I felt the same way the OP did until... I remembered all the hours I spent LFP versus actually playing XI because I didn't fit a party set up.
While XIV's combat and party system has flaws, it's geared towards everyone using their gaming time more efficiently.
I think one issue is the lack of difficulty it takes to learn a class which also deters people from alienating classes with steeper learning curves.
Yoshi's goal may be to add diversity through different Jobs because if they are evened out then it only becomes a matter of preference which is better than necessity.