This is a followup question to Why is the blue channel the noisiest?. The simple answer to that question is that sensors are less sensitive to blue, and therefore require more amplification, which results in more noise. (This is compounded by the fact that typical scene illumination like sunlight or incandescent lamps are lacking in blue.)
So, why are sensors less sensitive to blue light?
Is this just the way many sensors right now are, or is it more fundamentally a "law" of photography?