Not a scam. Higher prices give other benefits outside of safety. Better venting or aerodynamics. More fashionable. Might be more likely to have a "free replacement if you crash" type of deal.

I am surprised that the article has no mention of MIPS, Wavecel, or Kineticore, because looking at the study itself I found its discussion of rotational vs linear injury to be the most interesting bit, in relation to popular discussions in the cycling community. It points out that

Nine best performing helmets were equipped with the rotation management technology MIPS, but not all helmets equipped with MIPS were among the best performing helmets. Our comparison of three tested helmets which have MIPS and no-MIPS versions showed that MIPS reduced rotational kinematics, but not linear kinematics.

Which is pretty in line with my expectations. They only had one Wavecel helmet to test unfortunately, but had this observation:

Interestingly, the helmet with the Wavecel technology, designed for rotational risk mitigation, produced the lowest linear risk (0.141) in our cohort of 30 helmets, although its overall rank was #13 due to the high rotational risk (0.301)

Which is very counterintuitive. And no Kineticore mention, though they do say

There are several other helmet technologies that are currently available in commercially available helmets. Although these technologies were not within the helmets selected here, they warrant testing according to the protocol used in this study

In the US, motorcycle helmets are held to a DOT specification, which are okay standards. Buy when talking about brain cases, DOT spec is kinda minimal acceptable designs. Snell certification is an additional, more rigorous set of standards, and in my experience, those helmets are generally more expensive and, in my experience, a better helmet to wear and use.