OK, barn cats are great. On the farms where I've seen them, they did not get into the house as pets. Wild, nasty things. PET cats are exposed to injury and illness when they are allowed out. That is no way to treat a pet. I'm not a "cat person", but lived with hubby's pet until he died - had him euthanized when he got cancer. He was a sweet, affectionate, trainable cat. I would not have let him run loose for anything. Whilst we had him, we had an injured cat crawl into our condo atrium late one night - obviously injured, suffering and on death's door. He had a big, infected wound on his head. I put a bowl of water down for him, then called the animal control folks. Nice lady came to get him, said his wound was infected and full of maggots. She didn't want to tell us they would euthanize him, but it was obvious that he needed to be put out of his misery.
Cats also trade pheline viruses - I don't want a pet of mine to go through that. Mouse traps are not expensive.