State of Machinist 7.2

[Absurdity]

I mean on the one hand we ask for failure states and skill expression (Black Mage discussions), but then we don't even want walking casts where you commit to the button you've pressed?

I think it's pretty obvious why walking casts on filler, like in pvp, aren't good as added "commitment".
It doesn't work in PvE because there is no decision to make on whether or not to commit to it. You have to keep your GCD rolling and you have to use your filler or you will quickly fall behind in heat and battery generation, messing you up for the rest of the fight.

There isn't a situation where you can just decide to delay your "cast" of Split Shot because you know you won't be able to slowly waddle into the safe spot for the next mechanic, that option simply doesn't exist without a fundamental rework to how a vast majority of job rotations work.

DNC, and by extension NIN already have 'caster mechanics.' DNC dance steps, and NIN Mudras ask you to do a series of zero damage 'do nothing' steps in exchange for burst damage -- kinda like PCT's Motif, and Muse system that asks you to take a 'do nothing' action in exchange for burst damage. I don't think, and I don't think they think that DNC should have walking casts as evidenced by DNC not having them in PVP unlike the rest of the phys ranged. DNC (and GNB) do have walking channeled abilities, which yes please add this mechanic to PVE as well -- imagine being able to move while using Flamethrower.

There is a major difference between Dancer's steps, Ninja's Mudras and Picto's Motifs compared to Machinist's walking casts.

While the first two also can't be readily cancelled they do not limit your movement and consequent ability to not fail the increasingly frequent mechanics spam.
Picto's Motifs on the other hand have what Machinist would be lacking, the freedom to wait until you find a window to commit to the cast safely.