Oh yes, I know cats can have aggression problems! But it is usually brought on by someone (Dog or person) invading their space!
I was bitten by a cat when I was 7. I still have 4 perfect little scars on my right forearm from the teeth and a long scratch going down my wrist and thumb from a claw. And no one still knows what happened and my mom witnessed the whole thing.
Scared? Invading their space? The cat was in MY driveway and I did nothing more than walk by it. Next thing I know I had a cat hanging from my arm and my mom came running and literally had to hit it and knock it off of me.
And since it was a "stray" and ran off, I had the pleasure of getting 11 shots into my abdomen to prevent rabies and had lovely bandage changes to deal with and nasty antibtiotics to take. Personally, the whole experience sucked and NO ONE, especially a child, should ever have to deal with it. Moral of the story: if whoever owned that cat had kept in inside, I would have never been bitten by it.
And seriously, trying to justify cats and creatures that don't bite unless provoked and don't cause damage as they just innocently mind their own business is futile. Cats carry highly contagious diseases that they can and do spread among the rest of the cat population (FIV, FeLUK, FIP), they can carry Rabies, they can have an ecological impact in the killing off of birds (here in LA they seem to have an afinity for endangered species) and squirrels, and they do seem to enjoy destroying people's personal property such as cars and tarps and b-b-que grill covers. They enjoy using other people's bushes and even the frontdoor mat as their personal potty. And they could care less about trespassing onto property where they are unwanted.
For the record, my dogs have killed a neighbor's cat that was in my yard when I let 2 dogs out. Butch busted through a fenceboard the other day to get on that part of our property in the back we could not fence (due to underground gas pipelines) and killed 2 kittens out of a nasty, emaciated, fleabitten litter that my husband and my neighbor's husband had to deal with (& nobody enjoys doing that). They carry fleas with them. They carry ringworm with them.
All in all if you want a cat, fine. But if you want me to keep my Pit Bulls from roaming loose and destroying your property and using your yard as it's toilet and bringing fleas to your home, then I suggest you show the same courtesy with your cat.