Probably because this talk of skull-shape and less intelligence sounds a lot like phrenology - an old psuedoscience used to determine the latent abilities of a person, based on their skull shape. Which ultimately was related to their race - and used to look down upon different people groups.
Once you believe there is a strong causation between skull shape and intelligence, the racist conclusions write themselves.
I assume good faith on the part of the GP, though.
I've read a bit about them and most sources say this, 'they were more encephalized and even in absolute terms had larger brains, but probably were not more intelligent.'
I didn't have any idea anyone would interpret this as racist, wtf?
The discussion on skull evolution I reference here is also mentioned in the OP. How can I be accused of racism and not the OP? That isn't consistent.
Ha! Pump your breaks tiger; no one is accusing you of racism, people are makimg the observation that some could make that interpretation, amd such interpretations have a marked history in America.
Don't get hostile or defensive over a misunderstanding, please.
I don't know much about these researchers but I'm sure their research will be used by those who believe ridiculous things like this and will definitely use it to drive their own racist narratives. You can count on that happening.
Once you believe there is a strong causation between skull shape and intelligence, the racist conclusions write themselves.
I assume good faith on the part of the GP, though.