Nobody owns the Bitcoin name, is called decentralization and Bitcoin Cash is a fork of Bitcoin, not an altcoin so it makes sense use the Bitcoin name.
Uhh, altcoins are called altcoins because they're alternatives over the granddaddy cryptocurrency, which is Bitcoin. Bitcoin Cash could use the name, yes, but like every other Bitcoin fork out there, it is, by definition, an altcoin simply because it's not the original Bitcoin.
I acknowledge that Bitcoin is open source, and everyone could make a fork that takes a different scalability approach, but claiming to be the original is nothing but fraud.