Anyone who's ever argued that you shouldn't feed crows because it interferes with nature hasn't figured out that crows already adopted to urban human-inhabited environments, and feeding them quality food (cat kibble is cheap and works) is very much a net positive. If you see crows with white feathers, that's malnutrition, and you should give them something good to eat.
I once lived in territory of some ravens, and it was a deep pleasure to gradually become friends with one. It took maybe a year of consistent effort, but eventually he'd come hang out with me outdoors. I would say bits of Poe's "The Raven" to him, and when his turn came he'd respond with soft, friendly mutterings. He especially liked to visit when we'd grill and eat outdoors, as there was nothing he liked better than some some bone with bits of meat and gristle left on it.