Sure. I disagree with letting a cat outside for several reasons.
Fights, disease, getting lost or stolen, hit by a car, picked up by cruel teenagers (like the ones that set a cat on fire in their barbecue recently, just for kicks and giggles), killing wildlife, getting parasites such as fleas and ticks or internal parasites such as heartworms from exposure to mosquitos or from eating wild mice, moles, and birds that they catch, getting into poisons like spilled antifreeze, picked up by lab-hounds to sell to for experimentation, attacks by wild animals or dogs, getting caught out in incliment weather and becoming ill, getting picked up by the city shelter and put to sleep if not located swiftly enough, getting into places where they become trapped or injured and are unable to eat or protect themselves, getting shot, annoying neighbors by getting into their garbage cans or making nuisances of themselves, being trapped or poisoned on purpose by said annoyed neighbors...the list goes on and on.
And yes, some of those risks they do run by being in the house...even indoor cats can get fleas and ticks, but the chances of it are GREATLY reduced.
I've lost four cats that were allowed to go outside, even if it wasn't often. I have yet to lose a single one kept strictly inside.