I simply provided some counterexamples.
Furthermore, white collar or not, I doubt that many would contend that Kafka or Einstein were some sorts of models of "success" if judged by their jobs, and few would judge them "geniuses" solely by looking at what they did for a living.
The fact that Wittgenstein gave away his inheritance is completely irrelevant. We were talking about jobs as marks of genius, not about inherited wealth.
However, I will grant that being born in to a wealthy family, being given a first-rate education, and being surrounded by highly accomplished individuals (as Wittgenstein was) does usually give the beneficiary a tremendous head start over most people.
I would certainly have bet on someone born in to Wittgenstein's highly privileged position making something of himself than on someone born in to poverty.
That said, plenty of people born in to tremendous wealth squander it and their lives. A couple of interesting, relatively recent documentaries on the subject are "Born Rich"[1] and "The One Percent"[2].