How did the play offend the Abbey Theatre audience to the extent of causing the "playboy riots"? Was the production itself partially responsible?

Synge's The Playboy of the Western
World reveals an Ireland in love with violence.  This is the truth the play
reveals.  The characters in the play make a hero out of a man who kills his own dad. 
They put him on a figurative pedestal and celebrate his warped action.  The people of
Ireland have a warped sense of what to value. 

And, of
course, the hero doesn't even really possess courage or ability or anything of the
sort.  He doesn't even finish his dad off, and when the dad reappears, he cowers before
him.

Ironically, the riots caused by the performance of the
play weren't due primarily to the Irish being angry because they are portrayed as so
violent and ignorant in the play.  The riots were primarily the reaction to the swear
words and rough language in the play.  This, too, is
revealing.

Synge reveals the truth about the Irish in
Playboy just as Joyce does in Dubliners.  Of
course, the revelations apply to the rest of us, as well, not just the
Irish.