Cats don't have to be the pains in the asses they were represented as. I live in a household with four dogs (You got that right - four. A lab, a collie, a chow, and a daschund - four medium-large, one small). On top of that, we have a cat, two rats, and four tanks of fish.
We live in a three-bedroom, two bath house. And guess what? Two bedrooms are entirely animal-free, the house rarely smells of piss (rarely being that the puppy still has his 'oops' moments), and the worst damage are the dug-up flowerbeds. On top of which, the four dogs are in the house the majority of the time.
You know how we acomplish this?
Say it with me, people.
Responsible Pet Ownership. Or companionship, if you're the touchy-feely-sensitive type.
That means walking the dogs every day, playing with them, obedience, et cetera. But we're not talking about dogs. We're talking about cats.
Cats will not piss the entire house. Believe me, they won't. Once they learn to use the litterbox, they're set for life. THAT IS - if you do it right.
1 - Litterbox quantity and maintenence. Litterboxes have to be clean. By that, I mean scoop once, twice a day, change once a week with a decent scrub, et cetera. If you have mulitple cats, guess what? Sometimes you need multiple litterboxes. The major reason for cats not using the litterbox is it isn't clean enough.
2 - UTI - urinary tract infection or other health issues. If the litterbox is clean and the cat has been regularly using it, then suddenly doesn't, it's time to write down those symptoms and take a trip to the vet.
3 - Behavioral issues. Consult a behaviorist or research yourself. You CAN out-train bad litterbox habits - it's not easy, but it can be done.
Bonus - you can also teach your cats to go in the toilet. My previous cat always took a piss in the toilet. It was awesome and made cleaning SO much easier.
On household damage -
Before the cats hit home, they have their own scratching posts. They may have multiple scratching posts. Climbing and acrobatics is essential to cats - so big posts, safe bookcases, et cetera are a MUST.
About claw damage? Hi. There's such a thing as soft paws. Petco and Petsmart sells them. They are cheap, soft little caps that go on the cat's claws and they are changed regularly. They soften the claws so they don't do damage to skin, carpet or upholstery without the inhumane process of declawing. You want a declawed cat? There are plenty in rescues and shelters that have been through that proceedure that need homes.
Declawing requires breaking and severing of the toe BONES. It'd be like having a part of your finger broken off at the knuckle. During the healing process, it can also lead to infections due to scraping the litterbox. Declawing is inhumane, expensive and can lead to medical problems if not done correctly. Soft Paws are cheap, low-maintanence and the cat doesn't even notice a thing. Which one makes more sense?
Next - Training. This bullshit about not being able to train cats is an outright lie that people tell themselves to let their cats get away with bad behavior and justify their own laziness. Some cats are just as easy to train as your average lab. Most aren't. Most won't do the 'sit, stay, come' deal, but you CAN train them to do a variety of things.
You can train them to not jump up on places where they aren't wanted. You can train them to not scratch carpet, go into closets, or rush out of the house (if they are indoor cats, which most, if not all, should be in this day and age). You can train cats to coexist peacefully with people. Like I said, with some cats it's a piece of cake, with others it's some work, but it CAN BE DONE.
Enrichment - cats need to have fun. That means different toys, a birdfeeder they can watch by an open window, different, healthy treats, so on and so forth. Little things that make a big difference to how they behave. Playtime is a MUST - they bond with you and get tired out, so they are more content, healthier and less prone to mischief. If you don't entertain the cat, the cat will entertain himself - most likely with your socks or drapes.
Grooming - groom your cats. Take them to the groomer if you must. Trim their fur. Do this regularly and shedding won't be an issue. Or be so minor an issue that a quick roll-down with tape is all it takes and you're good to go.
If I can manage it and have a happy, healthy household of pets like I do while working 10+ hours a day and having a very active social life with plenty of hobbies, I do not see how the mom and daughter cannot manage it with two cats. It is completely unreasonable to devote an entire ROOM to an animal. Believe me - I've been there, done that, and it does no one any favors. My bedroom has my dog's crate and my rat's cage - it is not an 'animal room'. The livingroom is the hubbub of life for human and animal, as is the kitchen. Every living space is SHARED with the presumption that HUMANS are paying the rent and humans are dishing out the food, so humans come first. Naturally, we make exceptions - like sweeping more often, toweling muddy paws off, and watching where we step.
But that's us, and our household. Two cats shouldn't be a problem. There are many people who manage a very clean, very neat, very unobtrusive way of life with two cats.
Like I said, it's called responsible pet ownership. I'm sure the woman and daughter loved their cats, but I see no other reason as to why they'd ruin and run an entire room and put the dad through such hell.
I don't blame the dad. Honestly, if they can't step up to the plate, they shouldn't have cats either. It's mean to say, but them's the cards. If they can prove themselves responsible, on-top-of-it pet owners and take the time and effort to symbiotically introduce the cats and maintain them in their lives, then Dad needs to stop being such an ass and relax.
In general, he was a jerk to say such horrible things when they were grieving. But YEARS of this? I do not blame him one second. There is such a thing as compromise, and compromise sometimes requires work and bending of wills on both parts. So does pet ownership. But, like with pet ownership, it doesn't have to be a piss-smelling hell-on-earth.