[Xcelerate]

> I'm not sure why both spur an immediate sense of revulsion in me

I get the same sense of revulsion, but I know exactly why. Because almost everything in that matrix can be learned within a day or two. Take any experienced programmer and pick out one of those concepts in the matrix that he/she hasn't used before. It would take very little time to grasp the concept. This isn't like teaching yourself homotopy type theory with only a calculus background.

VP trees — have you ever heard of them? Neither had I until I needed to quickly search and partition a set of 3D points with periodic boundary conditions. It took about a day to become an "expert" on these trees and implement my own library. Isn't that a much more valuable skill than pushing yet another kind of data structure and its properties onto an "interview-ready" list of useless facts?