The author conflates several things into the label "SV": the private capital, the founders, the startup execs and so on. but surprisingly it barely mentions the engineers that are perhaps SV's most defining characteristic.

Now to address the article, the current ecosystem of companies in SV and the people it attracts is the byproduct of what venture capitalists are willing to invest in, which is itself a consequence of what the economy wants and the kind of ventures regulators allow to succeed.

So, if you want to point fingers asking why aren't tough problems solved you should start by asking yourself why is it that those are so much more capital-intensive to solve in the first place. And more importantly, what could be done to make them more attractive to private capital.

Of course, there's a narrow category of problems that are intrinsically capital intense. But many more are just artificial moonshots i.e problems that aren't that hard if not for the many roadblocks and hoops one would need to go through to formulate even a basic answer.

How long would it take to get a railroad network going in 2017 v. 1830s?

tl;dr: the entities influencing the incentive structure are more to blame than the individual agents trying to optimize for their own KPIs.