I used to have cats but despised how cruel they were in the food chain. Unfortunately it is their nature though humans are much worse of course but should know better! Hmm. Nature has to prep it's own food, whatever it may be....as for having cats for pets....depends on how you feel.
Are any animals gentle and not killers? I doubt it, even dogs under pack instinct turn to killing. This is our world like it or not but I still am not au fait with cats which for some reason kill just because they do.... So to ansa your question is don't like like them for that reason but there's something about most 'pets' that aren't good.... I would keep mine inddors if ever I had cats again. That prevents the massacre of birds and other animals. Kind or not, have them and prevent or let them enjoy their natural behaviour? Our choice.