At the very least - why hasn't anyone come up with a flat kit and/or tools compartment? I get that drinks are tough, since it has to be sanitary and easily accessible on the go.

But a flat kit, on the other hand, doesn't have to be either. It only needs to be accessible when stationary, and needs some mechanism to keep stuff from rattling around - both of which are easily enough solved.

(Beyond the 'add this to your bike' type solutions offered by Trek et al. I'm talking something inside the frame)