I totally understand that and I did say that I wasn't just referencing this cat specifically, but I feel that so many people are quick to put down an animal they consider to be suffering just because a human feels they would suffer in the same situation. Animals don't feel sorry for themselves and in most cases are just happy to be alive

They move on and make due with what they've got, and we are quick to put human emotions on them.
If this cat is in pain, I agree it would be best to end her suffering. But if she's not in pain and can lead a generally good life, maybe she'd be okay. Maybe they can attach something to soften the ends of her limbs? I actually read an article not long ago about a cat who had both hind limbs amputated and got a prosthetic set attached!
Maimed Cat Gets Bionic Legs : Discovery News
Layla can get around, that's true, but she still drags her back end around and is liable for cuts, scrapes, bruising, burns, anything that she can't feel and we need to watch out for her. Her tummy and butt and knees weren't designed for dragging! Her legs can catch on anything and could break and she wouldn't even notice! So there are liabilities with any of these special guys, but I really feel that a lot of them can still lead happy lives!
I'm not trying to argue or anything, and I'll say again, if the cat is really suffering and in pain, she should be let go.