Hope you're not including me among the cat haters, Paul.
We did have to put one of our cats down--he was on the road to racking up multiple 1000's of dollars of vet bills for a recurring problem. When you have a small child in the family the decision becomes much simpler, IMHO.
What I
didn't appreciate was how our vet dealt with the whole thing. Judgemental/guilt trip followed by overly melodramatic "ceremony" as she put the cat down. Made me and my wife miserable, and the cat wasn't too excited about the trip to the vet either.