I disagree with that. Cats are meant to be outside and free, not caged up. Predation is sad, but its part of nature, and rabbits are considered pests-they are under no protection by law because they breed like, well, rabbits. Cats help keep rodent population down, and keep in mind not just cats kill for fun-dogs and wild animals like wolves kill for sport regularly.
Disagree all you want, but it is the truth. Cats should not be allowed to slaughter wildlife. People will gladly let their kitties be 'free' even though they have the potential to single-handedly
wipe out an entire species with that freedom. Thankfully there are leash laws that keep dogs contained, and fines often levied in the cases where folks do let them roam. Dogs I find go strait to the animal shelter. If their owner cares enough to spring them, they have to pay that shelter the fee for their stupidity, which helps support that shelter. All that I've dropped off have had owners, by the way.
There are better ways to manage a rodent problem, like maintaining feed systems that eliminate waste. A cat that
might kill a few rodents here or there, or many animals that are not nuisances, like songbirds, is not an efficient rodent reduction tool.
Not to mention, if you can your cat to die an early death, then letting them outside is the way to do it. FIV and FeLV transmission from other cats, cars, aforementioned dogs, humans who harm animals etc. are all threats to a pet whose owner will not keep it contained.
Most natural predators do consume what they eat. Yes, wolves do occasionally hunt for sport at times when prey is abundant. But dogs and cats do it almost exclusively for fun, so there is no comparison there.