From the very interesting first link:
Karl Marx allowed for supply and demand, quoting Adam Smith himself, and I believe, describing the status quo of the era:
" It suffices to say that if supply and demand equilibrate each other, the market prices of commodities will correspond with their natural prices, that is to say, with their values as determined by the respective quantities of labor required for their production."
I don't think that this disagrees with the classical economic theory you mention, in any way. Would you to care to explain your point in a little more detail please? If anything it's one of the refinements that you speak of.
I'm not being dishonest here, I genuinely can't spot the difference. I have difficulty in spotting what aspect of biot's statement is inherently communist.
In Marx's own view on how things ought to be, paraphrasing, communism was a world in which each gave according to their abilities, and received according to their needs.
In this communist scenario, what each person contributed has no bearing on their compensation. So by supporting the current status quo, biot is not in my opinion expressing Marxist views, in fact, quite the opposite.
In fact, I've heard people denounced as communists for wishing for wage caps.