While it's clear that the vast majority of us do not agree with Draper's comments here, let's not attempt to discredit someone based on their (wealthy or otherwise) financial background.

I took this to mean something like "that explains how he has been able to become and continue to be a high-profile venture capitalist despite having a screw loose", rather than "that explains why he has a screw loose".

His father was one of the earliest of the modern venture capitalists. And among the first in California, circa 1959 (just two years after the founding of Fairchild Semi).

https://en.wikipedia.org/wiki/William_Henry_Draper_III

> And among the first in California, circa 1959

His grandfather founded the venture capital firm in 1959. His father was an associate that joined at the time of the founding.