It started in the original version of FF4, where Yang can use a move that is essentially Protect; then in FF5 you could use Chakra, which healed some HP and removed basic status effects; Sabin in FF6 could use Mantra and Spiraler; and the Monk class in FF Tactics was insane, since he could heal HP and MP for several characters at once, remove most status effects AND revive dead characters.
Then it returned yet again in FF9, where Amarant could do tons of white magic-based moves.
What's the logic behind all these obvious support commands?
Can it have something to do with the fact that some monks in real life are known to have certain healing skills?