Actually, my best hypothesis is that, remembering that the Gates Foundation, which is the organization Gates is actually involved with now, works a lot in government/policy circles, Bill himself might have views that are more common within that circle that within the tech community. Whether that means that he is taking this point because he has more information, less information or just different priorities, I do not know. I don't even remember if Gates took any position on the original crypto wars.

I personally find that the balance of arguments weights much heavier on the side of security and privacy, versus surveillance, and that creating this tool and setting this particular precedent would do more harm than good. I can still imagine a world in which Gates disagrees with that without being knowingly evil, though.

Actually, when it comes to Gates in particular, I admit that when I was younger I spent a long time thinking of him as "knowingly evil" (or at least selfish to a extreme degree) for completely different reasons. Later I realized that he might have simply put priority on different ethical axioms than my high-school self did... and in the balance of things might end up having been a higher positive force in the world than a negative one, by far, see e.g. https://en.wikipedia.org/wiki/Malaria#Eradication_efforts . This doesn't mean I agree with him on the issue at hand, though.