That is because cats aren't powerful enough to do so. I am sure there are plenty of cat bites and scratches that happen, but they aren't serious enough to warrant a hospital visit. Cats suck. Has a cat ever saved someone's life? Are ther police cats? Are there search and rescue cats? etc. = NO because cats are basically semi-wild animals that have about as much character, and intelligence as a rat. However, eventhough stray cats are an epidemic in many areas - I would still not advocate banning cats.
What you need is to get to 'know' a cat....then you will be a changed man. Even the Pope says animals have souls and I have learned from experience that cats have character, purrsonality, are funny, lovable and great company....I'll never live without at least one.