This gives a pretty good argument.

Short version: the American economy has become more competitive -- that is, good, new companies are more able to displace entrenched powers (which is probably part of why those entrenched powers turn to government so much to help them now). And returns on capital are getting lower. This article suggests that's because the value produced by people is, more and more, going to the people who produce that value, which is a good thing, and to consumers, who are getting cheaper and better goods, also a good thing. Those who produce value, by and large, are those who are good problem solvers, and who work well. This is also why I'm pretty staunchly opposed to let the government take over most things -- I don't think the best people are in government anymore, if they ever were. Now (and hopefully for the foreseeable future), there are much better opportunities to do good and to make money outside the government than inside it. So, most top people avoid government. Fifty years ago, I suspect that wasn't the case -- I would guess that government offered a much larger share of opportunities for young people with talent. At the very least, the risk/reward profile 50 years ago skewed more heavily towards government, for sure.

This certainly dovetails with what we're seeing here at AoPS. We're not so much capital constrained as we are people-constrained. I'm guessing we're not the only business that feels this way. I sure could use a cloning machine...