I understand your reasoning, but I respectfully disagree. The reason I think its important that ALL sites use HTTPS is that by encrypting everything "important" data becomes indistinguishable from "unimportant" data. This helps the security of the herd by making it more difficult for an attacker to identify what packets to collect and expend their compute resources on. In addition, anything we can do to normalize the use of encryption in such a way as basic crypto knowledge becomes mainstream is a win for the security of everyone.

The fight isn't about a hacker stealing your passwords. The fight is about every single entity on the Internet being hostile towards user privacy with a strong monetary and power incentive to use any and every inch you give them to take a mile. So let's not give them any inches. Encrypt everything using the strongest cipher suites available and the best methods of identity verification we have. It may not be enough, but it's better than giving up and letting the baddies win without a fight.

And to clarify before the inevitable reply points out that HTTPS isn't sufficient by itself to protect user privacy. Yes, I understand that. But it's an important basic building block for doing so.