Is it possible to bathe your cat and not get scratched to bits? Of course! Now it is much easier if you start when your cat is a kitten and basically train them to accept the water. Older cats can be bathed too though. Although your cat doesn't realize it right now, after some tender loving care and a little shampoo, he will appreciate it.
Why would you want to bathe a cat? Well, they can get dirty and can become flea infested just like a dog, so they do need a bath in these instances. Sure a cat bathes themselves and most of the time that is sufficient. If your cat happens to get into something like car grease (walking or sleeping under a car) paint, any chemicals or pretty much anything they get into that you don't want them licking off their fur.