Cats, healthy ones at least, are natural predators, as others have pointed out. Just watch them at play with each other or with their toys and they simulate hunting, stalking, ambushing and killing prey.
As a cat owner for many years, I have no qualms about heading off for a week-end and leaving my cats outside. I don't leave out food for them because this only attracts vermin - mice, rats, grey squirrels, jack-daws, crows, pigeons, etc. I only leave them water in the summer as despite the fact that my cats drink domestic water in the house, once outside they make beelines for rain-water puddles for a drink.
The beauty about cats is they're self-sufficient and the relationship with their "owners" is a mutually beneficial and rewarding - food, shelter, care and attention as well as opportunities to take a "walk on the wild side" occasionally for the cats and vermin-free houses and gardens for the "owners".
Unlike the much less intelligent, pack-oriented, and owner-dependent dogs, cats are fiercely independent and are capable or switching "owners" if the current relationship is not to their satisfaction.
As per VOR's post above the whingey cat is probaly whinging for eh, cat of some kind.