Comment 55 for bug 28835

As you can see if you read the whole history of the upstream bug, this problem should be mostly fixed in the current development version. David Zeuthen and Alexander Larsson have improved the behavior of Nautilus so that removable devices have an "eject" option that unmounts all of its volumes and performs some hardware actions (power, get out a disk...) if needed. The "unmount" term is only used if several partitions are present on the disk and you want to remove only one, which will only happen if you are already using a relatively complex environment.

There's also a mockup suggesting to make partitions children of the device, which is not implemented:
http://bugzilla.gnome.org/attachment.cgi?id=136310&action=view

Though, I think this papercut is solved, since I don't believe we can completely avoid the term "unmount" when we're dealing with really technical contexts. For standard cases it's now hidden.