I am much more confused by your statement, really. I don't mind if people break the rules of grammar and make fragments for effect (because it's the way we talk, afterall). But IF she proof-read it, THEN it wouldn't make sense? Uhhh, sure.

Housecats do not belong outdoors. A single cat will kill (not hunt, kill for "fun") a hundred small animals every day. Clearly this is catastrophic to environments. This is why many state and national parks have a kill-on-sight rule for non-native cats.

Our arrogance as a pet keeping species? If you think it's arrogant of us to keep pets, I'm surprised you don't think it's even MORE arrogant that we let them intrude upon and disrupt an ecosystem that has existed long before domesticated cats were brought to N.A. (which means they are introduced). The animals cats hunt are smaller and weaker, but there are bigger animals that hunt the cats themselves. Coyotes and raptors are more than happy to take advantage of the easy meal that dumb cats who haven't learned to escape predators offer.

I wasn't necessarily disagreeing with you, just adding a bit of input.

My cat is a perfectly happy and healthy indoor cat. From a kitten I took her outside on a harness and now she is quite content with it. So she gets to go outside and no animals are killed.