For debugging mainly.
Lets say I'm making a multiplayer SHMUP and each spaceship and enemy has a set of FSMs attached to a child gameobject that displays it's collision boundaries and collects information on where the collisions are coming from and who fired etc.
I need this information to make sure everything is working as intended but once happy I want to be able to turn off that FSM in every object (which will make the game look better and more performant). I don't want to have to delete this debug gameobject in case I need them again later. So if I can set up a FSM that says 'Press X - deactivate all FSMs with Tag 'Debug' and Press X again turn them back on again'
Does that make sense?