For the defenders of Google's (and previously Apple's) behavior, I'd like to point out that if any of this was for the sake of security, developer ID certification would be left to an independent international organization and not be under company control. That would also clearly have legal advantages.

That's how it's done with domain names, with security advisories and disclosures, etc. That they don't do it for developers shows that it's about control and anti-competitive business behavior (preventing other app stores).