thebritt, I agree it is not real nice, but you have to accept the fact that it does happen, and will continue.
Many, many farmers keep 'barn cats' that are basically wild, to keep mice down. And obviously they do not want to spend the money on having those cats surgically altered by a vet. It is logical then, that since they have oodles of experience castrating other animals, they will castrate the barn cats in the same way.
I know many, many people in our area who do this on a regular basis without complications. Sure, there is a chance there is complications, but it is low.
I will admit I have castrated barn cats for people with either a knife or rubber ring. The way I see it, it is the lesser of two evils. I know these people arent going to take the cat to the vet to get him neutered, and I figure if I do it, it is better than leaving him intact and just leading to a higher population of cats that wont be desexed.