Why are many aspects, such as pricing of oil in Euros, of "defending the dollar"  given almost no play is the regular media? 

Perplexing. 

Here [annotated , original] is the first plausible attempt I've seen to answer that question.

If you have other priorities, here is a very short form of their argument:

• The dollar is a fiat currency.
• As a medium of exchange it patently works just fine: people will take it in exchange for stuff you value. And it has pretty much the same value over the days or weeks between the moment you receive it and the moment you spend it.
  
• But as a store of value , it requires trust-in-perpetuity in the US Government.  (A  a store of value either has intrinsic value - it is not a debtor's promise to pay, or it is a debtor's promise to pay where the amount of the debt is constant over centuries.  Prior to 1971, the US dollar was a credible promise to pay a foreign government 1/35 ounce of gold.  Now, it is an "I owe you nothing note".)
• The dollar has huge, worldwide float.
• The dollar is held by the central bank and/or treasury of many countries as a 'reserve': as if it were an asset with intrinsic value.
  
• There might well be a run on the banks if it were agreed that pricing oil in euros would cause substantial dollar inflation.
• The Federal Reserve 'Banking Cartel' (the article gives an extensive justification for the use of that appelation) owns (!) a significant portion of the shares of the mainstream media.