That wasn't always true.
MCH got blocked from entering PF during 6.2 because it was simply miles better to grab a Dancer or a Bard due to better performances.
6.2 W1 only saw around 7 machinists clearing P8S against 400 dancers. Warrior and Paladin got the same treatment.
It's very cute to support the idea that locking jobs out of PF is toxic but the reality is there, MCH has been underperforming and playing it feels like being an extra weight to your group.
MCH players just want to feel impactful and useful, as much as if they were playing other jobs. It's not rocket science.
