It's a decision of Shinten or Kaiten. It's small but a potential potency loss and does requires skill, even if it's muscle memory. If this is insignificant, then all actions are insignificant, and we might as well be watching a cutscene.
It reduces required skill and game feel.
They could have combined certain AoE/ST actions like they have for other jobs instead. The feeling and required skill would be unchanged and keybinds reduced by greater amount.
If we remove Kaiten, then following the same logic (lack of complex decisions, action reduction), Shinten should be removed too. Shinten has even less decisions in its use.
