Quote Originally Posted by Kabooa View Post
Lets say Summoner brings 500 damage bonus from Devotion.
I think I'll just stop you right there, because defining the additional damage from raid buffs as a flat number is putting the cart before the horse. Like your dancer example, raid buffs are percentage based by nature, whatever number their contribution turns out to be in reality is entirely dependent on what job is being compared with those buffs. If it's 500 when a 15,000 dps blm is on the other end, it's going to be 430 when it's a 13,000 dps bard. This puts a natural damper on combining multiple support jobs without any heavy hitters to cash in on those buffs. The rest is just a matter of tuning to ensure the margins between the different combinations of jobs are sane.

As for the matter of machinist output compared to black mage, that's an issue of inter-role balance and has nothing to do with the matter of support vs selfish jobs. I don't think machinist players would be very happy about being treated like second class citizens though, just because you think their job is 'easy' or something. You may as well ask, why play machinist if blm is going to get special treatment? I didn't see any warning saying machinist was designed as a job with a lower skill ceiling on purpose.

There is also the matter of the 1% mainstat buff you get for each unique role you add to the party. It's basically a forced-diversity quota to encourage you to make balanced parties. Even if black mage were slightly worse off, as long as it's better than losing 1% mainstat, that is your reason for bringing black mage. And like I said, it's telling that the jobs are balanced so badly people are considering ditching the ranged for that reason - they're so bad even a free 1% mainstat buff isn't enough of an incentive.