True in shares view you get taken to your default share and there is no back option to get to the list of shares / drives.That´s because those plugins don´t use a shares view and therefore don´t need a back arrow.MPTvSeries, MovingPictures etc don't have it and people seem to do ok with those ...
As MyMusic and MyVideos suport shares views, there must be a hint that you are in a subfolder.
And yes, I do use a HTPC keyboard with inbuilt mouse pad, and I can tell you that i´m much faster with mouse (e.g. in menus) then via remote, and I also know from many posts in the forum that there are a lot of mouse users out there
Also means you can use MP with one of these remotes where only cursor and ok buttons work.
still they can be annoying....