Xpost @ johnquiggin.com
There's a simpler but also more seductive quality with argument from authority.  In simple biological terms, gaining knowledge requires energy expenditure.  This means that the value of any knowledge gained must be totted up against the energy expended to produce it.  In our evolutionary history - ie the integrated period of our brain evolution - starvation was a regular threat.  Simply running a large brain requires 20% of our energy, many other very successful mammals use considerably less.  This produces a quite different knowledge strategy to what you might find in an epistemology text.

We prize cheap information.  We congratulate ourselves in having got to the "gist" of a situation on very limited information.  The Climategate emails was a perfect example of this: virtually no one read the thousands of emails involved but a lot of people were willing to regard the three words "hide the decline" - without context - as as incontrovertible proof that the researchers involved were crooks, and QED that the other thousands of climate researchers were too.  No doubt they congratulated themselves on their incisive intellectual capabilities in forming this judgement.  This is "gisting" gone crazy.  If it weren't so tragic it might be funny.

Unfortunately, this kind of thinking is not limited to anti-AGW types, it's everywhere. 

This is also the key reason why science took so long to get off the ground: sitting around for days, months or years try to find outliers that disprove hypotheses just isn't on in a nutritionally limited environment.  Our brains contain Baysian inference circuitry gated by some pretty worldwise energy expenditure calculations.

The argument from authority strategy is an energy saving knowledge strategy that is built-in or natural to us.  The basic logic: "X says so, X has a pile of goodies/status, therefore X is probably right" is obviously logical piffle but is a reasonable biological strategy, in an evolutionary sense.  Unfortunately, we (in general, not you or I :) are not that good at distinguishing where the pile of goodies came from and whether obtaining them required any relevant mental or physical effort at all.