I think I have done a fine job of feeding them game birds, song birds, chipmunks and squirrels for quite a period of time. The problem is these native animals have essentially now been wiped out of an area that can be measured in
square miles 
We are not talking about a suburban back yard where these cats ate the lone cardinal that visited the tree a landscaper installed. We are talking about acre after acre of loss of wild species due to the cats that have gone wild and found the native animals to be easy prey.
But feeding them also feeds other pest species like raccoons. The difference is the raccoons are native and belong out here. Unless they get sick, they stay away from the buildings/house. But when they find food they become ravenous pests that will do anything they can to get it. So you are setting up a situation where the raccoons and cats will be fighting, and while my 90# Akita dog has shredded a few raccoons, I can tell you that no feral cat would stand a chance against an angry raccoon.
So if I feed the cats, which is clearly impractical on this much land, I set up a situation where the cats will fight raccoons and some of the cats will dies (a good thing) but where the raccoons and perhaps other wild animals may become dependent upon the food and start to multiply to numbers that are higher than nature can normally maintain. Then when/if I stop feeding the cats all the animals that have become dependent upon the food would starve, or at least endure severe hardship.
Further, feeding them does not resolve other issues like the fact that the cats will still kill the birds that come into this area. With the cats here no pheasant or woodcock can survive long, which is why we no longer see those species. The low nesting birds like bluebirds are also gone, their nests raided by cats and babies eaten. Chipmunks and squirrels have suffered the same fate, death by cat.
So in the interest of good land stewardship, something that I’m sure St Francis would also advocate, the cats must go.
But, if I set out a 1# pile of food per square mile that was shown in the map on previous posts, I’d have to buy a 25# bag of cat food EVERY DAY. I’m not sure how many HOURS it would take to feed them, but I’d obviously be traveling 25 MILES over the course of the day to get from food station to food station. My utility cart drives a top speed of 12 miles per hour on flat paved ground, so figure I could average 5 miles per hour through paths, across the fields. At that rate I’d spend 5 hours just filling the food stations every day, plus I’d be paying for a 25# bag of cat food every day. Plus my actions would be showing bad stewardship (as outlined many times in the thread). Plus the fact that I have a job to work 10 hours a day, and a family that probably doesn’t want me to spend 5 hours a day, every day, feeding cats. Not to mention the Catholic school bills that I have to pay, I suppose we could send my daughter to public school so we could afford to pay to feed the cats?