Yeah, I wonder why so many people keep repeating "study STEM" instead of "study Engineering or Finance or Medicine", considering the fact that "S" (Biology/Chemistry) and "M" (Math) seem to be pretty weak.
I meant that for a major that's generally considered to be hard and lead to a lucrative career (it's part of "STEM" after all), it's not that different from Pol Sci or Business (and it does worse than Accounting or Economics, both of which are non-STEM), which most people probably wouldn't expect.
I would expect (but do not have data to support) that those who do accounting/econ who take a more math-oriented approach do better than those who take a less math-oriented approach.
STEM as a whole is basically the entire top half of that chart. Even math, which you call "pretty weak", is (taking the average) as close to CS as it is to communications, and much closer to the top cluster than it is to the bottom cluster.
So I think "study STEM" is perfectly good advice, particularly given that there will be shifts in the value of various degrees based on subtle economic changes.