~> Shaw idolized Stalin, Hitler and Mussolini as the world's great
~> "progressive" leaders because they "did things,"
unlike the leaders of
~> those "putrefying corpses" called parliamentary democracies.

Shaw was a committed socialist, so it is no surprise that he liked the
general principles of both national and international socialism.  As far as
Hitler in particular, my guess is that Shaw's opinion (like many other
socialists in the US and UK) was favorable until June 1941 and then did an
immediate 180 the day after Barbasossa.

~> early 1930s openly defending Hitler, mass murder and genocidal eugenics.

He was in favor of eugenics, but so were many others at the time, including
Teddy Roosevelt, Woodrow Wilson, and Winston Churchill.  I seriously doubt
that he was in favor of genocide.

~> In 1934, just one year after Hitler came to power, Shaw said: "If they are
~> not fit to live, kill them in a decent human way."

In context, the people he was talking about were incorrigible criminals. 
Every defender of capital punishment would probably agree with him.  The
connection between this and the holocaust is nonexistent.

 
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