Since Fedora 20, there is a hint when typing a password, according to https://bugzilla.redhat.com/show_bug.cgi?id=994237 it is a problem of gtk3-3.9.10.

There is clearly visible inspiration from world of hand held devices. Typing on touch screen is far from typo-free and such hint is useful. Moreover one can easily move/hide/rotate/tilt or somehow protect the device from password stealing. 

Situation on desktops is different. There are large rigid displays faced in on way where one can see what you're doing from afar, cloning on video projector etc...  And there are keyboards, not exactly typo-free but nothing that needed such password hint.

Benefit of showing last character is overwhelmed by big security hazard when one can easily peek over else's shoulder. In world where nations spy on their people this change appears to be ill and efforts for good user experience should not pave our way to hell.

There are other ways of helping users writing passwords, such as "show password" check box or a peek icon like in Windows 8.

I beg you to see the reason.