To start this article, a nifty fact, lactose intolerant are actually less developed human beings. This isn't meant in a cruel sense, just that they don't have the mutation to process dairy products like the majority of the human race now has. This single fact encapsulates why the palaeontological diet is bogus. We have evolved to eat differently than our prehistoric brethren. It is part of the amazing thing about humans as creatures, we have forced ourselves to evolve in our nature very rapidly.
A typical cave man (term used crudely crudely when one should just say early human species) wouldn't have the intelligence to rear animals, they hunt and gather. Hence, we used to be a hunter gatherer species. Therefore they had no means by which to acquire dairy products from the milk of certain animals. Pretty basic so far. But then the amazing human intelligence developed and we found a magic substance that is released from the various organs of certain animals that was nutritious, tasty and easily accessible.
The ever evolving human with their amazing grasp of how to use objects, animals and just about anything to the betterment of themselves, adapted to this rapidly (in the timeline of evolution anyway) expanding diet. We mutated and began to process these amazing substances of milk and cheese and it became a staple of historical diets for decades. So why is it that some people believe that a prehistoric diet would be better than the balanced nutritional diets of the present to accommodate the common man?