The comment is not designed to take a thread into a flamewar, it's a legitimate grievance based on living in habitats destroyed by released domestic cats. I don't hate cats, I own an indoor cat. Removing them from a habitat they do not belong to is no different than government agencies encouraging the removal of snakehead fish from U.S. waterways. They're both destructive, predatory species hurting native species, the only underlying difference is that cats garner the irrational support of humans to exist in a feral/outdoor state and destroy with impunity (cuteness bias?).
This is one reason the guidelines include: "Comments should get more thoughtful and substantive, not less, as a topic gets more divisive." Cats are one hell of a divisive topic. (So are dogs, but I think less so.) It maybe doesn't quite sink to the pit of flamewar hell with cyclists vs. drivers but it's close.