I don't think there would be any particular issue with making MP management relevant if there was a failsafe to prevent mistakes from completely bricking the job unless you carry around super ethers.

Like if there was a GCD button that recovers some MP per use, so there's still consequences for messing up but you also don't become useless for an extended period of time (like MNKs in HW were 2/3 into a long fight without getting Goad).