The On-Line Slang Dictionary defines a wazzock as "an idiot; an annoyingly stupid person".

Thus the term may not be entirely appertinant to Bitherscrum, other than at festival time.

BTW., it should be distinguished from wazzcocker, which is a noun meaning "Someone who likes to go and get wasted". Now that, I would have thought is a perfect summation of the Blitherscrum Festival regulars, bearded or not.