I have two dogs. One is crate trained and the other is not.
We never crate trained Zoee because I am a light sleeper and she was a restless sleeper so she kept me awake. When we leave the house she goes in the bathroom, that is her "crate".
When we got Taggart I decided to crate train him. I was a little skeptical due to the fact that he had been a kennel dog for 6 months (well, we don't know what his life was for the first 6 months). But we crate trained him to sleep in his crate at night. That way we aren't fighting for space on our bed with two dogs.
He is such a sound sleeper, he doesn't keep me awake with moving around. And he has a bladder of steel and can hold it forever. Not by my choice....I'll try to get him to go out before bed and he just looks at me like I'm crazy. He know goes into his crate for bed at night before we even tell him to. He also goes in there if/when we leave while Zoee is in the bathroom.

If that's "inhumane" then so be it! Then I guess there are lots of us here on Pet Talk that are inhumane.

Oh yes, back to the original post.....I never heard of crating a cat to potty train it. Strange....