The fact that all of those that decided they would become military pilots became military pilots, without exception, suggests to me at least that they were perhaps not operating on the same level playing field as everybody else.
Why not? They're just a visible example of it, I'm certainly aware of at least one father and son who're both fast jet pilots, it's just that as they're not royalty you won't have heard of them. I'm sure if you had the time you could go through Air Force and Navy lists for the last few decades and find more examples.