Insecurity by obscurity
"Two weeks ago, the pair received thanks from Intel for working with the company to disclose the bugs responsibility. "
Well, had Intel published all the architectural details about a decade ago, none of this would have been necessary. Someone at Intel took the decision to put this into their chips but not publish how it worked bother to make it secure. (The two versions of that sentence are entirely equivalent to anyone who knows anything about software development.)
And whilst we are on the subject ... I'm told that AMD have a similar feature. Have they documented it? Or are they enjoying Intel's discomfort without realising that the same inexorable logic applies to them.