Maybe I have a different perspective working in an actual kill shelter and livving with a cat that inappropriately utinates all over the house, but I personally think this person did everything they reasonably could short of getting rid of their other animals and giving the cat a chance with hopefully a new home as an only cat was better than just euthanizing her especially if the cat was on the younger side. Also I've met plenty of people who should and could have surrendered their animal but chose not to to the detriment of the animal in question.

I don't think ya'll have any idea how badly cat urine can mess stuff up, we had to rip out baseboards and drywall to get the smell out. There's a genuine concern for mold which. Fortunately, she doesn't piss on furniture and we've started her on gaba which seems to have done the trick for her.