I think a large part of the issue has to do with government policy as it relates to science. I notice that many politicians reason in terms of "producing more science" as if it were a commodity good that should be produced and exported en masse.
The problem, then, is that the current academic system actively encourages people to pursue academic careers without disclosing the reality of the situation. They push masses of people through undergrad, then grad school, then post-docs, until the end of the line whereupon most people hit a huge brick wall.
I'm all for promoting research in STEM fields, but simply upping the quota of Ph.Ds won't cut it. As far as the U.S. is concerned, I think this has more to do with turning a blind eye to the dismal state of public education than anything else. It enables politicians to say "we trained 200% more scientists", while conveniently omitting the following truths:
1. Virtually none of them will be employed in the sciences at a level that warrants a doctorate.
2. For all the chest-puffing we do, we still get humiliated by the rest of the civilized world in terms of education.
3. Those people actually employed in research positions in American universities are majority foreign.