OP's thoughts with comparing feeding kittens vs feeding f/t mice and rats isn't accurate, because OP is talking about cat overpopulation aka feral kittens and newborn housepets. That isn't equivalent to f/t rodents, because our f/t rodents are specifically produced and bred for food. They're clean and free of parasites and free of meds or poisons, and most importantly that they're bred and sold from the get-go in order to be reptile food.
So an accurate comparison to using kitten overpopulation as food is more like: would you feed feral rat pinks to your snakes?
That's really it, there isn't much to talk about.
But if one was asking if one day, people somehow run out of rabbits (lol) and start businesses of breeding kittens as large reptile feeders... That would be more ethically accurate to your rats/mice/hamsters comparison.