(1) Someone in a forum makes an "offensive" comment that's a show of support for political protestors which might anger an authoritarian government that not so incidentally happens to be of a country with a lot of customers of a product the forum supports;
(2) Someone in a forum makes an "offensive" comment that's an insulting attack on other users based on race, and the offensive nature is pretty clear to most people -- at least those who don't agree with the attack -- even if it happens to be prefaced with "I'm not racist, I'm just saying...".
These are not incredibly difficult to distinguish between. The commenter in the first case is supporting a marginalized group; the commenter in the second is attacking one. Punishing the commenter in the first case is kowtowing to an authoritarian government for baldly monetary reasons; punishing the commenter in the second case is showing support for an oppressed group in a way which is probably not going to bring you any financial benefit -- your company's accountants are not going to step in and say "you need to ban Pepe1488 for consistently sounding like a white supremacist because if you don't, it could cost us hundreds of millions of dollars" -- and whose PR benefit is, at the least, debatable. (The people in the oppressed group might love you, but if there is any press coverage whatsoever you are going to be inundated with threats.)
There's a principle involved here which can lead you to boycotting Blizzard, but that principle is "we should support the right of people to protest against their goverment." The principle isn't "you should never ban any offensive speech of any kind at any time because to do so inexorably leads you to taking the side of authoritarian governments." (Use a slippery slope argument once, and you'll use them everywhere.)