There is a type of professor that's exactly like a VC. The guy who wrangles a team of postdocs writing grant applications, farms out the funding to students and postdocs for them to do the actual work, and then puts his name on the resulting papers.
I think what they're saying is that there are plenty of researchers/professors with ego, who think they're God's Gift. At the same time, there are many more researchers who are very humble and realize their contributions are a small part of a larger whole.
In startups, it seems that a strong ego is an advantage - if not a necessity (see: Elon Musk, Adam Neumann, Steve Jobs). There's an attitude (usually explicit, but sometimes implicit) of "we're disrupting the _____ industry and changing the world!".
Overall, I think you can find strong egos in any industry or job. However, my guess is that if you (somehow) ranked researchers and founders by ego, you'd find that the distributions were quite different. My guess is that the majority of founders have strong egos, with a long tail of those less ego-centric and that researchers would be quite the opposite - generally less ego-centric, with a long tail of strong-ego individuals.
Right, but a professor specifically is someone who in most instances can at best be said to have once done some research before graduating into managing researchers (grad students). It's like saying "programmers don't behave like _____, based on my experience with mid-level managers in technical organizations."