A fair point. It's been a while since then. I didn't recall that.
That said, he's just an easy example. There's a few other people who could be used. There's a billionaire who was an early Bitcoin adopter for example.
And it certainly would have been possible for Notch to become a billionaire without hiring people. The company only had 25 employees in 2014, and was doing $330million in revenue every year. There's certainly a path he could have tread to still becoming a billionaire without hiring anyone.
It would have been harder, taken longer, and not been as profitable for sure, but doable.
Sure, but that argument is specious as hell, right? Like, if everyone in the United States decided to give you a $5 bill, does that instantly make you a bad person who exploited labor to get where you are?
"There is no ethical consumption under capitalism" is simply a rhetorical device to outline the flaws in the system. It completely breaks down when used as justification to villainize someone.
Your position could be equally stated as, "anyone who has more money than me is a worse person than me, and anyone with less money than me is a better person than me." It's a misuse of the "no ethical consumption" idea on its face.