But it's never explained properly.

Wouldn't want to rile up the masses.  Better to confound them with marginal pricing theology, lest they turn to seeking mechanisms that could reduce "the highest level that can be borne by a given level of demand."  Better also run some more articles about the bounty currently provided for all by the wonders of the market to distract support from those who would point out that the small number of players and the nature of the supply and the demand mean that this situation doesn't really satisfy normal definitions of a market.  Point out that (some) alternatives could be worse, but don't mention that some might be better.  Alternatives are comples and scary.  

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."