The only known owner of Perfect Hair is Carlos the Scientist. Some worry was caused when The Perfect Hair was cut by Telly the Barber. Carlos attended a town hall meeting about the doors at Radon Canyon; and although "tragically shorn of his locks", Old Woman Josie tells Cecil that he was "still absolutely perfect, and smelled of lavender chewing gum." However, Cecil later mentioned that Carlos was again "perfect of hair" , implying his hair wasn't perfect when it was short.
We can estimate that Carlos' hair is roughly mid-length, given that Cecil mentions it growing back to its original perfection from being cut "very short" in the space of just under a year.
There was never a reason given for Carlos' haircut, and/or whether or not he'd wanted it that way or liked Telly's work.