They took the risk, gambled on Bitcoin when others were too afraid to. They were rewarded for their gamble. Seems fair to me.
They didn't just invest a few million, they also stuck their necks out in a very public way and made efforts to bring Bitcoin to the investment masses (via the ETF). A failure in Bitcoin would have reflected very poorly reputation-wise.
Of which they put 1/5th of the Facebook shareholder money into Bitcoin
And to do that they had to be at Harvard at the right time, which involved being born in the right circumstances of course.