I've never found the Blue Man Group particularly compelling - their presence in the running gags of Arrested Development aside - but if I was in Toronto and had the opportunity, I'd buy a ticket purely because they're showing some backbone in standing up against union goons, concerned only with their own sinecures and claims of entitlement. If the fact that the cost of union dues isn't necessarily being passed on to the end consumer means tickets might be a few dollars cheaper, that's a bonus.

If you were to be less glib, there's a fairly straightforward reason for the BMG's actions spelled out in the third paragraph. "It is an employee's choice to join a union -- not an employer's place to require it." If union members are individually best qualified for a job, great; if not, they'll hire non-union technicians and support staff. It's the supposition that union labour (in and of itself) is somehow sacred with which they would seem to be fighting.

Psst...the tickets are cheaper! And its a great show! It's a great way to re-vitalize our city!