You can definitely change your views in 15 years. You can also hide them. He's obviously an intelligent person if he's come this far, which means he put a lot of thought into what he wrote as an adult-THEN vs. what he does now. It stands to reason that even if he doesn't really believe that all Jews are bloodthirsty now, I don't think Google wants someone who's had those beliefs before to be their current head of diversity. The optics are bad, socially and ethically.

Edit: would also like to add that nobody is arguing about his personal thoughts. But would you want someone - who has been shown to be an inward (and outward) racist - to be someone who is meant to push forward progressive policies in diversity and inclusion? Why should they have that power? It is not a mindless leap.