Blizzard as a private company is under no obligation to offer 2nd amendment rights of freedom of speech, as a Hearthstone tournament is far from a public forum. That doesn't mean their customers have to agree. Firing the casters who had no prior knowledge of this statement and physically duck under their desks to show their complete lack of association with it, is something that many have taken issue with, regardless of politics. Or you could not, that's up to you.
But as the rest of Blizzard's subs indicate, most people aren't supportive of Blizzard's indirect condoning of an authoritarian regime that is currently hurting thousands of real people.