Not only that, but the red text doesn't appear until it's too late: AFTER they've put their sensitive information into a form, which probably spirited it away with JavaScript before one can change their mind.
Not true: Currently the "info" indicator appears on first interaction (which _could_ be after they've auto-completed everything, but may not be). This is changing though: In Chrome 68 the info indicator will be there on all HTTP pages, without form interaction required. So this change just changes it from "info" to red warning.
If you type fast, you can probably get a whole username (or personal name, or street address) in without seeing the red warning. (That said, it looks like it _will_ show "not secure" by default, even before you type anything in, on HTTP; it just isn't emphasized unless you enter data.)