I think it has a great deal of worth, especially considering how much people in his (and most) industries operate with twitter as a public-facing manifestation of yourself.

Secondly, not wanting to do business with someone because they are an ass...sounds pretty reasonable to me.

It's reasonable in the individual case, but the effect is still forcing someone out of the industry for making blasphemous, err, offensive jokes. (not, as far as we know, being an ass at work) This seems uncomfortably similar to blacklisting someone for being a Communist, even if it's an emergent blacklisting and not a top-down edict.