I will say what my roosters think. Toss me into the wild with the predators before inviting me on the one visit for dinner. Former the bird has at least a slim chance to re-home himself. The legal and responsibility issues still stand in why you should not get point where contemplating such an end point.
As much as I dislike the idea of abandoning any animal, I see your point. But believe that depends on the landowner's situation.
To others:
I am now thinking that "abandonment" could be more "setting free" depending on the situation. For instance, some people own enough land that they can choose to free range a bad bird. If you set up a covered roost at the edge of your property or up in an old tractor shed some acres out for bad bachelors to sleep under... with a water tin, he might fare pretty well.
Others seem to imply that a rooster can be taken to an open wood or field and just left. Dumping the animal on public land or any other private land is not only wrong because you're leaving your animal behind, but you're leaving it on someone else's land. Abandonment is bad because a person is saying, "I don't care any longer what happens to this animal. I'm actually hoping a predator picks his bones clean soon so he's off my hands."
People should also know that in most places, dogs run free, and dogs will kill for the fun of it and not eat.
It's more than an opinion that someone has the right to have. It's an ethical and moral issue.
Depending on the situation, this abandonment some are rooting for, makes you just as bad as those people who would drive slowly down my dead end street, open their door, shove their dog out, and drive off quickly.
(The pound set out one trap for eight free ranging dogs in heat, and my chickens trembled in fear as these dogs began to form packs and look for food.)
If you don't want to eat him, at least feed a poor family. Craigslist him. Mean rooster. Free Chicken Dinner for poor family. Someone will want him.