Do you blame Dan Harmon and Justin Roiland for Rick and Morty Fans causing physical destruction to several McDonalds franchises this last Saturday?
They don't have control of their fanbase the way a dev has control over a playerbase. The OW team can create rules of how people play, and they can also enforce those rules. The creators of that TV show can maybe like, make a tweet? But they can't enforce jack shit about what people do.
Overwatch basically had no rules about behavior, and what rules they did have weren't enforced by Blizzard. The systems they have in place in the game also contribute heavily to perceptions that end up creating toxic situations. They had so much power to do something about this ages ago, and they chose not to. That is 100% their fault.
The fact that it took three fucking thousand reports for somebody to get a one week ban is the most insane shit I have ever seen.