The problem is that supporting enough of the PC hardware to build a graphical system from the ground up is a many hundreds of thousands, if not millions, of lines of code commitment. It takes many many bug reports over several years to stabilize something like that.
You could perhaps do something on a newer, simpler, and well-designed and documented architecture (say an ARM dev board with a network interface to an X/NX/VNC/browser interface). But even Google continues develops Android on top of Linux for a reason.
You could perhaps do something on a newer, simpler, and well-designed and documented architecture (say an ARM dev board with a network interface to an X/NX/VNC/browser interface). But even Google continues develops Android on top of Linux for a reason.