Instead of punishing, human colleagues can suggest that misbehavior has less desirable consequences than good behavior. Some special topics. An infectious disease could spread like wildfire otherwise. In a multi-cat household, there will be curiosity, but the quarantine reduces stress for the new cat and reduces the level of disagreement when there is an introduction. What's more, the new cat will by that time regard the quarantine place as a place of safety if other cats are overwhelming.
Quarantine is particularly helpful in socializing a feral kitten or cat.
It allows the kitty to master the territory, learn to accept human visits that respect kitty territory and limit the number of stimulations the kitty has to deal with in adjusting to a new environment. Each success in very short human visits builds confidence. The kitty may need to hide at first, watching as food is brought and litter box is cleaned, but as that 48 hours ends, there should be some brief and tentative interaction. Make sure the quarantine area is comfortable and has opportunities for calm interaction with humans. Obviously, a little pleasurable contact with just one or two humans goes a long way at first.