I'm a bit surprised that no one in that post highlights that with 50 BTC reward the total just ends up being a nice number that is rounded to millions (almost): https://www.wolframalpha.com/input/?i=%28sum+210000*%28%2850*10%5E8%29%2F2%5En%29+n%3D0+to+32+%29+%2F+10%5E8 . Yeah, I have seen people having some amount of hype around this magical number...