American labour organization pretty much no longer exists which is quite convenient for this sort of thing - it's quite likely this went across a few folks' desks who bowed their heads because they thought they'd be singled out for objecting.
I praise the employees that are walking out today - but a number of them were involved in this happening and didn't feel empowered to speak out and oppose this before the poo hit the windmill. That tends to be par for the course in modern america (keep your head down because anyone who objects is fired) and while it has some short term benefits for upper management they end up wholly owning their problems and nobody is going to call out a big mistake like this one before it goes public.
Lastly having worked in the gaming industry the turnover is quite high, I don't know if Blizzard is better about retaining senior folks, but it might be that everyone who would have the confidence to stop this before it exploded was long ago canned because their salary grew out of the range where Blizzard wanted to keep them on.
