The best thinkers are not intellectually humble but intellectually ambitious

I think there's a terminology problem with this article. "The best thinkers" isn't well-defined, but if you're thinking of Einstein or Feynman or people like that, they're marked by a clarity of vision and the ability to ask the right question. They're not entrepreneurs or driven individuals outside their self-chosen scientific fields. They're curious, they want to know more and they know what is known and not known. Feynman's "what is inertia" story about his father. Einstein's "what do you see when you ride a beam of light?".

And keep in mind one of the most significant indications of what Einstein was able to do was his four 1905 papers, followed by general relativity in 1915. If you want to define "thinker", doing a set of publications that were good enough for the Nobel in Physics as individual papers rather than as a multi-decade set. Hell, they didn't even mention Relativity in his citation!

Gleick's biography of Feynman included the story that he could "climb Mount Blanc barefoot" in his discussion of genius. Feynman was inefficient, as he ignored the literature so as to figure things out himself. Yet he was able to see a visual solution to QCD that Dyson showed was the same as the wall of mathematics of Schwinger and Tomonaga. He avoided the trappings of academia, and didn't even raise many grad students or postdocs. He wanted to do physics and he wanted to convey this to others.

If "great thinkers" make large constructions, start businesses or change industrial or technical processes, people like Einstein and Feynman weren't in consideration. Such activities would bore them, probably quite quickly. They wanted to know why. Physicists could not always follow their trains of thought. They were fortunate to be active when great discoveries were being made and they lived long enough to create and disseminate information.