Honestly I think it would be kind of cool if osu! took advantage of positional audio for the hitsounds. It would just add a nice little effect to it that would add more depth and feel to the game. The audio doesn't have to be overwhelmingly one sided, just an offset depending on what side of the screen it's on. If it bothers people just add an option for it in the audio tab. If there are technical reasons for this not working, it's understandable.