As far as I know that Bard support is far more consistent since you don't need experience with the fight or your teammates in order to provide the basic additional critical increase with the addition of Foe's Requiem versus needing to align damage windows with Wildfire.
Troubadour and Hypercharge are two different sides of the same coin (Doing more Physical/Magic Damage versus taking less Physical/Magic Damage) but I say Troubadour comes out on top simply because it has a 3rd option available with the HP Buff. The Bard has more support options than the Machinist therefore it gets the title of Support Job if you ask me plus if you believe in the parsers and DPS rankings floating out there right now the Bard is doing more damage than the Machinist right now so that's always a plus when you got somebody trying to decide which one to play as.
What
I'm not disputing that Bard has a slight support edge, but that's not an accurate description of the MCH side of things at all. Machinist's current kit is still superior support to anything Bard offered in ARR and HW, so to label them as a 'selfish DPS job' is a misread.
Going in order: Hypercharge doesnt belong in a Troubador comparison, because it's part of the offensive kit, not the defensive kit. It's up for roughly 30 seconds every 120, giving you 25% uptime on a flat 5% damage buff; since Trick Attack is up every 60, every Hypercharge should naturally stack. Any fight where DPS checks are severe enough for it to matter will generally also involve people planning out cool downs and burst windows. Functionally, the offensive rDPS buffs for both jobs math out to be very close. Nobody wins on this alone.
Hypercharge isn't the Machinist answer to Troubador, Dismantle is. Dismantle is 10% damage reduction to all damage--Physical, magical, darkness, untyped, whatever--cast by a mob in the next 5 seconds. It's up every 90, meaning you can use it twice as often as Troubador, it has no rotation reliance on the MCH (because useful BRD defensive buffs require making sure the right song is off CD at the right time). Troub is easier to put up, lasts longer, but does not buff the bard--meaning if you toss it up to help the party survive, either the bard needs extra babying or they're just going to die while their defensive buff keeps the rest of the party alive. Given how Dismantle works, it'll reduce the damage to everyone from a boss-cast AOE.
I'd give Bard the uncontested defensive support edge currently due to Minne, because Minne is nuts, and they get the preferred range title at the moment because of the MCH tuning problems and design problems people wish I'd stop bringing up. But neither of those things makes thinking of MCH as 'selfish DPS' at all a sensible reaction.
Like, I don't at all disagree that Bard is currently in a better place. But "bard is TRUE SUPPORT, MCH is SELFISH DPS" is a bizarre response given that MCH is still more support-y than ARR or HW bard, and the game as a whole has shifted towards a more constant intermingling of support and DPS responsibilitiies; I'm not saying recommending bard is wrong, but that sort of oversimplification and hyperbole based on what seems like a shaky understanding of MCH is just bad info to give a new player. There are enough valid reasons to pick bard.