An understanding of security will reveal that security is not a binary state of affairs. It's perfectly reasonable to trust known-imperfect mechanisms like the iPhone fingerprint reader to keep honest people honest and discourage ordinary muggers and thieves. I don't need military-grade access control for my personal iPhone, I don't want the inconvenience that would necessarily accompany it, and I damned sure don't want to pay for it.

And the Google Chrome guy is correct in all respects: it's not reasonable to expect an application to provide security that's redundant with security provided by user accounts on the OS it runs on. It would be better to teach users to create separate accounts on their system, if they want to hide their local passwords from other members of their family.

It is perfectly reasonable to expect an application to provide more security than the user account provides because in the real world, we know that people don't always lock their computers. Not all applications are risky, but one that centralizes a users credentials is clearly so.

Pretending otherwise is simply not acknowledging the real world.

Name one security technology that is 100% foolproof. They don't exist. So the point isn't to rely on one thing, but to rely on many things that, used in concert, increase the risk, complexity and cost associated with subverting the entire system--not its individual components.

In the same way that you'd afford extra scrutiny to a government agent making claims about what encryption methods to use, you should afford the same scrutiny to companies making security claims who are documented collaborators with the TLAs.

An ad hominem isn't always a fallacy, especially when the credibility of the speaker is legitimately in question. Saying they're automatically wrong would be fallacious (not to mention silly), but questioning credibility based on actual, documented behavior is not.

The main argument is in the second paragraph.

Anyhow, thanks for noticing :)

Security is not binary.