I've always worried that it's worse than that.
Even if there's plenty of deep thinkers (which is what slow thinking is in my opinion) - there should always be some people with good fortune and circumstances to push at the peripheral. I honestly do not see that today in Silicon Valley - I see a lot of useless bullshit and superficial replacements, there's only a handful of people out there keeping it together.
However... poverty of Time is not likely to be the main constraint unless you live in the Middle Ages. Many intellectuals have taken jobs which enable them to kill two birds, merely being physically active and forced to be active by a job that requires it is a genuine cognitive advantage - not to mention the infinite distractions that can smear your available leisure time such that you produce nothing of value. Most aristocrats did not belong to the Royal Society.
No - the real problem is that we're too synchronized. We think alike - we have a 'frame problem' of our own.
Being here on HN or on the Internet in general is not an advantage. It at first appears to be valuable in the sense that you understand what exists and who is doing what, the context. That is I suspect the opposite of what we need for true innovation.
For true innovation you need to connect up with 'the network' once or twice a year - and the rest of the time fuck off and do something good (ideally with a small close knit group).
“[..]Although personally, I think cyberspace means the end of our species."
Yes? Why is that?"
Because it means the end of innovation," Malcolm said. "This idea that the whole world is wired together is mass death. Every biologist knows that small groups in isolation evolve fastest. You put a thousand birds on an ocean island and they'll evolve very fast. You put ten thousand on a big continent, and their evolution slows down. Now, for our own species, evolution occurs mostly through our behaviour. We innovate new behaviour to adapt. And everybody on earth knows that innovation only occurs in small groups. Put three people on a committee and they may get something done. Ten people, and it gets harder. Thirty people, and nothing happens. Thirty million, it becomes impossible. That's the effect of mass media - it keeps anything from happening. Mass media swamps diversity. It makes every place the same. Bangkok or Tokyo or London: there's a McDonald's on one corner, a Benetton on another, a Gap across the street. Regional differences vanish. All differences vanish. In a mass-media world, there's less of everything except the top ten books, records, movies, ideas. People worry about losing species diversity in the rain forest. But what about intellectual diversity - our most necessary resource? That's disappearing faster than trees. But we haven't figured that out, so now we're planning to put five billion people together in cyberspace. And it'll freeze the entire species. Everything will stop dead in its tracks. Everyone will think the same thing at the same time. Global uniformity. [..]”
― Michael Crichton, The Lost World
Silicon Valley is suffering by being too middle class - the hubris is coming out of the groupthink. I think it takes a peculiar mixture of working class and middle class thinking to do something really good. I don't think that's a new insight, it's in the plot of the 1927 Metropolis but sometimes a cliché is really true. The people I've met at HackerSpaces, the people who impressed me were always adept at dealing with a lot of information - a middle class trait, but had a deep blue streak in their character that is completely absent from the people I went to University with. Matthias Wandel and Bill Gray are examples I think.
https://www.youtube.com/watch?v=8wZ1v4PIsYI
http://www.velkess.com/