"The people that get Bs work for the people that get Cs, and the people that get As teach."
As I said, it's entirely possible that tech (or at least the quality of company I've worked at) is something of an anomaly, but I wouldn't be so quick to dismiss it as unrepresentative: it's not controversial at all that the importance of intelligence is rising fairly rapidly in the modern economy and tech may be more representative of the present and future than you'd think at first glance.
I think people are simply conflating GPA and intelligence. This is especially true given the study is from the NE liberal arts schools who funnel into finance regardless of their major. My math/econ double major was completely irrelevant during my 3 month training program where the brightest person in the room was an english lit major.
Yes, this is a very good point that I elided a little in my comment: I actually just wrote a different comment on this post about me not including my GPA on my resume because it reflected the fact that I miscalculated how much I could take on vs my actual intelligence (I ended up with a low-3s GPA and three degrees (all considered fairly challenging) in four years).
But I don't think that, at the population level, it's a conflation to recognize that the _correlation_ between intelligence and GPA (ceterus paribus) is pretty significant. The risk is in reducing the candidate to too few features, but that's not inherent to including the feature in your overall assessment.