Forgive me if I sound a bit slow, but I really don't see how the fact that some subjects scale more than others, and furthermore that some people exploit this phenomenon, necessarily leads directly to a "vocational vortex" of "[educational] mediocrity." The reason for poor educational standards is more a question of how much one values personal and intellectual development; I imagine that very few people revere their education as an opportunity to undertake "high scholarship for its own sake", and simply setting aside some statistical trickery is not going to redress this deeply-rooted problem.
Admittedly, yes, scaling perhaps provides an undue reward to a careless or lazy student doing certain subjects over a dedicated student doing others. However, this does not automatically suggest that poor scholarship is rewarded outright; those who are sure they are capable of achieving a 50 in a subject (for instance) are going to pursue their interests regardless, and be handsomely rewarded for their efforts.
On the less contentious points, I do agree with the writer's assertion that the focus on numbers, at the expense of true depth in study, is detrimental. Again, however, I imagine that the added educational depth he so desires would only be appreciated by a select few, highly self-motivated students: as he correctly identifies, most view education as simply a means to a vocational end. I don't think there's anything wrong with this worldview per se, although I don't subsribe to it myself.