Obviously I’m not advocating that people hurt cats, but the truth is that they are just as much pests as e.g. foxes, or pigeons, and there are people who feed all of those.
If you don’t want your cat to be fed then you really can’t let it out.
If your cat wanders into someone’s garden or house and they feed it then you can’t hold the person who feeds it responsible for that, and given your cat is an animal with its own instincts who can’t be held responsible, if your neighbour feeds your cat then the person responsible is you, for letting it out in the first place.
Especially if, as people here say, “the cat refuses to wer a collar/shouldn’t wear a collar because it’s dangerous,” etc.
The fact is that there are a lot of stray cats out there, some who have been born as strays but many who are abandoned when an owner moves, or who find their way home if the owner moves house. So it’s actually natural that people would feed them. The alternative is that many of these cats wouldn’t survive.
And I’d rather feed a cat, even a greedy one, than watch it slaughter the local birds.