With Bug #1025703 in the latest Firefox 38, Mozilla has finally decided to stand up for its users instead of catering to the banks that don't want the passwords remembered.
But the persistence of firms trying not to have the passwords remembered undoubtedly contributes to the easiness with which fishing attacks can performed -- if their users are accustomed to entering their passwords when returning to a tab after 15 minutes of inactivity in a given tab, on a whim's notice, fishing is just so much easier when they're all ready and willing. Compare it with the Password Manager approach, which securely stores the passwords within, and is pretty much guaranteed by design to only reveal them to the correct web-sites.
So, why do the banks continue to do this, the mouse and cat game of preventing the passwords from being saved in the Password Manager? Aren't password managers a good way to ensure no fishing can be performed on one's customers, since they don't even know their own passwords?