You obviously have a problem with this, and I have quite a few myself.
However, suggesting that these people thought about and found practical solutions in their everyday lives is surely not only demonstrated by the achievement of the monuments themselves, but through a long established academic and popular corpus that includes works and papers considering their approaches to illness and disease from the eminent Don Brothwell and the Archaeology of Disease through to such as Aubrey who thought the mental health of the people of this area was troubled through eating too much cheese, and Guy Underwood in the Pattern of the Past. I think it was Underwood who was suggesting that the sarsens were placed on water courses to act as a radiator not of heat but some sort of health convector to make those with spinabifida more comfortable. It is perhaps not obvious that greens have to be eaten to combat spinabifida, but if abstaining from eating through sickness one still has to drink but is still being sick it may not take the genius of those that designed Silbury to twig that it could be the water that was making people ill.
Still to be thought through undoubtedly, misguided it might be, perhaps even downright wrong, but I don't think it's all that spurious.
You say spurious I say spa-rious, let's call the hole thing off...
VBB