Hello everyone! Somewhat long post ahead.
OK, so the main issues with Machinist are somewhat low damage for a lot of trouble (its not that bad, but could be better) and that, compared to Bard, it brings nothing truly of note to the table. Yes, the job can clear all content given enough player skill but I would suggest something different.
Take a good look at Bards support capabilities (cross-role not considered) and now look at machinist.
Now take a second good look at Machinists moves; you will notice that, given the moves they have, the dev. team will never be able to squeeze enough unique support to be able to match Bards capabilities.
If you were to buff party members (for example, boost crit), which move would be able to do so? Kind of hard to put it there without making a whole new move or risk things getting silly, isn't it?
No, Machinist abilities are interactions between self, turret, and enemy. This is not exactly support type style, is it? What they do bring (again, not counting cross-role) is Dismantle (reduce enemy damage for a short bit) and Hypercharge (increase enemy vulnerability for a little time). That's it. These abilities also have a somewhat long cool-down making them less reliable considering their useful nature.
In Final Fantasies past, machinists were never really party support, but more crowd control and damage. Their tools and abilities mainly focused on dealing good damage and, occasionally, debuff a target with blind, poison or some other status effect. This does not work in this game either, as most bosses are not really affected by regular debuffs. Stun and Silence only work if a mechanic is involved, Blind is useless and poison is a DoT, which we had one but was removed.
There are also some machinists in the past that focused on elemental weakness fiddling but, again, this does not work in this game as elemental weaknesses are not a thing for enemies, only for us and only as debuffs for some mechanic.
Go back to Final Fantasies of the past. FFIV we had Cid, he had scan, hit hard with his hammer and an ability called Upgrade which added elemental damage to his attacks. Again, elemental weaknesses are not a thing in this game and we already have a self damage boost in the form of Hot Shot. Next.
Edgar from FFVI, he had machinist tools in spades and with them he would deal good damage, poison, flash and even attacks that ignored defense. He also had 2 ways of inflicting instant death in the form of a lucky chainsaw strike or the heat debuff with Air Anchor. Attacks that ignore enemy defense in an MMO such as this sounds all sorts of tricky to balance around so that is a no. You could say our Wildfire is a form of of the heat debuff. The heat debuff I speak is a debuff that would kill a target if they did a physical attack with it. Obviously, instant death stuff is a no in a game like this.
You see where I am going with this? Mustadio from Tactics only had stun, disable and petrify besides his gun. The Machinist from FF Explorers is more akin to what we have but their move set is all about dominating with lots of fast attacks, the gun drone (like a turret) and big damage. They also had other abilities but we kind of have them in one way or another. Check FF explorers firearms abilities for yourselves, you will see.
No, the way machinist is set up now simply does not work as a support DPS and will, in all likelihood, never be as desired as a bard in terms of support. No, they are more akin to Ninja in terms of tools than anything else. Hence this suggestion to the development team. Please consider making Machinist a full DPS job so that they can join the fray along with the others instead of warring with Bard over who is more worthwhile to bring to the more difficult content.
Who knows, it might just be what Machinist needs so they can really shine.