My grooming shop (Grooming Boutique in Las Vegas) is usually packed with cats. Long Hair, Short Hair and everything in between.
Most kitties are there for a haircut. Some are there once or twice a year and others are there every few months or more, some just drop in when they become matted (those knots or clumps of hair) and are getting a shave. A few cats see the groomer for a regular bath and brush (nails, ears, glands etc.).
Even the short haired cats get shaved often due to matting if they have a thicker coat or just to cut back on the fur flying around the house or not much time for regular brushing for the kitty mom's and dad's.