> It is not enough to use some strong passwords for the things you think are sensitive. Every weak password is a weak link in your total identity chain.

I get what you're saying here, but this is patently false. My HN account is not a weak link in my "total identity chain" in any way that matters.

Yes, obviously defaulting to strong passwords everywhere is a better default because you can make mistakes when judging how important a specific site is, but that doesn't mean that every site is critical.