I couldn't agree more and I'm surprised there are 'only' a few of us noticing the Android 'back'-button actually always opens the list of all notes from the last selected notebook instead of navigating back to the previously seen note(s).
If you just selected a note directly from the note list it makes perfect sense the Android back-button opens up the note list again, but most of the time I use internal links to go from one note to an other and not being able to go back to the previously opened note by means of a 'back'-button/swipe or other function, but instead always opening the list of all notes from the notebook you manually selected the last time doesn't make much sense to me...
As there is a dedicated button on the upper-left corner to open the note list already I have the feeling this might be a bug, unless this behavious is intended due to limitations on the Android platform.
The only post I could find about this topic was this closed one:
*edit: using Android v2.7.2