I agree that they may have done this for the wrong reasons, but I'd definitely argue that it's a step in the right direction. And honestly, even if this decision was made from a place of corporate greed, I say it takes what it takes to get scumbags their comeuppance. We have power as consumers, and we can use that power to send a statement to greedy corporate people. If the threat of our lost patronage can make backers and board members fire rapists, let's keep it up.
It might also be worth noting that many powerful, rich industry members accused of rape have not faced any consequences whatsoever EVEN when their crimes were brought to light by the press. So the fact that the Weinstein Company did it is no small matter.