I believe bitcoin forks have the right to use the word bitcoin. In fact, I think it's a good practice.
Take CU Sudo, for example. A fork of sudo later became the default implementation of sudo because the original development group stopped working on it. It would have been silly for it to call itself anything other than sudo, given its function.
Bcash supporters are intentionally trying to create market confusion by claiming that "bitcoin cash" isn't "bitcoin cash", it is "bitcoin", a different coin.
I think that's hostile.