Outraged, but unable to change this because Starfleet won’t allow him to alter the officially licensed hardware, Scotty pretends this computer doesn’t exist, in the hopes of it one day breaking down so badly Starfleet will let him replace it with something he made himself.

He's already replaced it, but has to keep the HW and remain proficient with it, in case Starfleet shows up for an inspection and he has to swap back to using it