I'm pretty sure "People are trained to look for the green, not for the lock" is newer and not nearly as widely known advice as "look for the lock". And it's pretty obvious just looking around non-tech-related sites that even the "look for the lock" advice isn't all that well received - so many sites use images of padlocks on the page to imply "banking grade security!!!", surely not _all_ of them are incompetent - I have a strong suspicion that at least some of those people are doing it as part of high statistical significance validated A?B tested funnel optimisations...