PIE - mirage of structure

Someone named Naso comments on the blogpost here:

An excellent image for this is offered by James Clackson, my old supervisor, in his 'Indo-European Linguistics'

"Reconstructed PIE is a construct which does not have an existence at a particular time and place (other than in books such as this one), and is unlike a real language in that it contains data which may belong to different stages of its linguistic history. The most helpful metaphor to explain this is the ‘constellation’ analogy. Constellations of stars in the night sky, such as The Plough or Orion, make sense to the observer as points on a sphere of a fixed radius around the earth. We see the constellations as two-dimensional, dot-to-dot pictures, on a curved plane. But in fact, the stars are not all equidistant from the earth: some lie much further away than others. Constellations are an illusion and have no existence in reality. In the same way, the asterisk-heavy ‘star-spangled grammar’ of reconstructed PIE may unite reconstructions which go back to different stages of the language. Some reconstructed forms may be much older than others, and the reconstruction of a datable lexical item for PIE does not mean that the spoken IE parent language must be as old (or as young) as the lexical form."

See, the whole thing is a 'mirage of structure'! That's what models in historical sciences are. In the absence of time machines, that's the best we can do. 

Then one gets a book like "Comparative Indo-European Linguistics: An Introduction" by Robert S.P. Beekes, and he has a whole chapter 3 "The Culture and Origin of the Indo-Europeans":

3.1 The culture of the Indo-Europeans

Reconstruction provides us with a PIE vocabulary.  It is fair to assume that the things which the reconstructed words represent also actually existed.  If there should be a PIE word for 'snow' then the Indo-Europeans would have known what snow was.  And if they had a word for 'plow' they must have had or know some kind of plow, too.

The 'mirage of structure' is ignored.  What happened to "stars are all not equidistant from the earth"? What is the evidence that "snow" and "plow" are "equidistant" stars?