Only if cat-people and dog-people don't intermingle.
But given how hostile many cat-people are (see sibling comment), compared to dog-people which tend to also enjoy the company of cats, I can imagine a timeline where this misanthropist branch of humans splits off, goes to live in trees and hisses at anybody that comes nearby.
> goes to live in trees
Mainly because they lost the ability to climb down.
Hmm, I've known a good number of dog people who dislike cats. Never read any stats on the ratio of cat-lover+dog-hater to dog-lover+cat-hater groups, though.