Calling them "Mopars" doesn't make it so either. There never was a Mopar Division that built and sold cars...in fact, all they ever manufactured and sold was parts.
It's all a matter of colloquialism and what people call things that they place collectively in categories. Therefore, for many folks, those are "Chevy" hoods.
There is no changing what people call things, just understanding why and what the names mean.