The media player is only the visible top layer of the multimedia framework, there are multiple layers below building a complete, powerful and flexible solution. Therefore, the problem is not the mediaplayer (well, only in terms of limited functionality, but IMHO it's quite ok at what id does, at least for my needs).
The main problem might rather be that the multimedia framework and its components such as gstreamer and pulseaudio are not yet perfectly optimized for the power of such a mobile device. OTOH, it gives developers such as me endless possibilites, such as seen in recaller, to build feature rich media applications with very little effort.