Look, sit back and really think: what is the point of new Classes? I mean, really; the game works perfectly with what we've got, right?

The point is to appeal to different types of players. I don't like the squeaky-clean "knight in shining armor". I do, however, love Black Knight styled characters. Thus, the Dark Knight is incredibly appealing to me. Consider that player who loves the Machinist, using a gun and tinkering with robotics. Sure, a Black Mage can also fill the role of Ranged DPS, as could an Archer, but it doesn't cater to the FANTASY that player wants. You're essentially telling him to play a character he doesn't like, on the chance that 60+ hours in, he can change to one he MIGHT like.

It's not about "putting in the effort" or having anything handed to you. It's about creating a more enjoyable experience, that doesn't feel SO overwhelming that a new player feels like they're too far behind to even bother starting.