The reality of things is pretty much as Astralis said. Each job has its own things to do. Until Mr. Crevox came in with his silly ranking that put DRG as being simpler than Summoner and Black Mage, people were in agreement. Monk is the most difficult/annoying. Dragoon is next in line. After that I think was Summoner. Followed by Black Mage and Bard respectively. I just did the same thing he did by feigning ignorance of the Mage jobs and simplifying them the way he did with Dragoon.

If a Monk misses a step, DPS goes down quite a bit. Same with DRG but not by as much as a MNK. Summoner and Black Mage, will notice even less of a DPS loss if they miss something in their rotation. Hence the lower amount of complexity as most people who have tried the jobs agreed upon (other than Crevox).

I love playing as a Dragoon (I prefer the FFXI version but this one isn't that bad). That doesn't mean that I haven't tried the other jobs though or looked into their optimal styles of play.