a) Shiny math and shiny languages are negatively correlated; the mathier a grad student is, the more likely he is to use Matlab and the less likely he is to actually know how to program. When mathier people write non-Matlab code, it is often (but obviously not always) very shitty. Now, there are ML people, but they're a small subset of mathy programmers.
b) The "Terran" description is closest to what you would think of as a normal hacker, but hackers generally care that what they make is good, and people who care about code being good are not usually characterized as "just getting shit done," since for example they rewrite code that works just because it's ugly.
c) Terrans, by which I mean hackers, can and do learn math and then become unstoppable. I imagine there's some Starcraft parallel here, but I haven't played it recently enough.