Because they can pay the substantial premium involved. Collectively, our interest in having as many people as possible moderately well-educated rather than just having a few who are outstandingly well-educated imposes constraints.
our interest in having as many people as possible moderately well-educated rather than just having a few who are outstandingly well-educated
I am compelled to note that our existing socioeconomic, and thus educational, systems operate pretty much the other way around: the revealed judgment of capitalism is that it's better to have a small elite of outstandingly well-educated rich people who can confidently exploit the mob of mostly ignorant masses.
1) Because the same effect and the same processes are displayed at the post-secondary level where capitalist forces operate more strongly than social-democratic ones.
2) Because the capitalists control the government, at this point, so government action is a good indicator of what the capitalist class thinks is best.