"Little or nothing to do with their success" is a bit far in the other direction.
NPR has this segment where they say there were only about 1000 people in the world who were in a position to start Microsoft like Gates was. He's very lucky in be in that 1000. But of those 1000 only 2 founded Microsoft. The rest didn't want or bother or care or see it.
Did that NPR report account for the fact that his mother knew the head of IBM from the Red Cross? Had that not been the case it's really a stretch to think that Gates would have made it to where he is today. (He would have been successful no doubt but on a much smaller scale.).
NPR has this segment where they say there were only about 1000 people in the world who were in a position to start Microsoft like Gates was. He's very lucky in be in that 1000. But of those 1000 only 2 founded Microsoft. The rest didn't want or bother or care or see it.