At least dogs have leash laws, and anyone who owns a dog who lets it run loose will get fined at least, or sued, or worse.
As far as cats being less troublesome, tell that to my dog who was inside her fenced-in yard, got her ears batted by a rogue cat in our yard, and had recurring ear problems for the rest of her life, ending up going deaf.
Tell that to my daughter at age 4 who was traumatized at discovering a decapitated squirrel on our front doorstep, let alone the health hazards had she been curious enough to touch it.
There are laws about picking up dog droppings in other people's yards, but cats can crap to their hearts content in yards and flower gardens. And cat crap smells 10x worse.
Cats should be leashed or kept inside, just as dogs are.
/rant
...wait, it's not a rant. It's just plain common sense.