There's really no "stealing" the brand, since it's technically a modified Bitcoin, they added the "Cash" on the end and they use the BCH ticker to differentiate themselves.
Rebranding might be good in the future, but right now their main selling point aside from the blocksize increase is that they're using the same block history as BTC. From that perspective it makes sense to consider it "Bitcoin" or if one thinks it's more in line with the original vision of Bitcoin, perhaps even "the real Bitcoin".
ok so someone copies one’s passport and calls oneself other one’s name and put a look like mask, but wears different better clothes maybe, now someone declares someone is the real one. The movie face off comes to mind
More like someone mostly copies the design of an old watch from the company they used to work for and says theirs is more like the original than the newer design / more Gucci than the current Gucci etc.
Or, someone who is not corrupt/officially considered police by the local government monopoly decides that he can still do better and calls his work "real policing" as opposed to what other men and women in uniform are doing.