Being self made is irrelevant, all that matters is society benefited from the value that Microsoft produced, and he was enriched accordingly. It's not complicated. Who cares if he had a leg up. Should we think any less of SpaceX because Elon had rich parents. Progress is hard, we need to welcome it how ever it comes, and reward those who produce.
His biography is quite clear on how lucky he was and how much his parents contributed to his success. Denying it is perpetuating a myth of a self made billionaire that simply isn't true.