I must've read this very differently. I rolled my eyes and skipped over the experience table. I've seen one too many programmers with literally decades of experience but still without a clue.
But the rest… I assume it's a matrix for a reason. Someone isn't a level log(n) programming mage, but he or she might be a level log(n) data structure and algorithm wielder, a level n^2 systems programming apprentice, and a level n requirements gatherer, or some other combination of strengths and weaknesses. It's still a lossy abstraction, but significantly less so taken that way.
But the rest… I assume it's a matrix for a reason. Someone isn't a level log(n) programming mage, but he or she might be a level log(n) data structure and algorithm wielder, a level n^2 systems programming apprentice, and a level n requirements gatherer, or some other combination of strengths and weaknesses. It's still a lossy abstraction, but significantly less so taken that way.