While getting scratched now and then is part of life for someone who raises cats, it is not normal to have one's cats scratch guests unless the guest has provoked the cat. It is not hard to teach them not to scratch and bite. It can still happen accidentally but it should never be a regular occurrence.
I guess it depends on the cat. I knew someone with a very territorial cat* that would run across the room to scratch/bite strangers ...or people it knew well. Walking past it? Expect a full claw swipe at the back of your legs.
The solution is to just put the cat outside or in another room for a bit not to mutilate it, IMHO.
*(What's funny to me is that I helped them choose the cat when it was a kitten because it was "a licker". I didn't realise at the time it was just making notes on us all to see how we tasted.)
