I think applying this idea to the current situation is preposterous. You suggested a stern denouncement from publishers barely related to the situation would have had the power to prevent the threats. These are individual behaviors which amount to terrorism, and they're deliberately anti-social.
Video game culture, like other culture, suffer from systemic and structural biases which unfortunately undermine non-default people from even existing within the culture without conforming to its hegemonic ideals. These systemic and structural biases are reinforced and curated by video game companies and publications, that constantly reproduce the same power hierarchy and prioritization of worldviews and identities.
Staying silent when you are partly responsible and have a demonstrative influence on this culture is an implicit approval of the status quo. And the status quo is currently that some gamers can't handle a woman making Youtube videos about their luxury hobby.
Game companies and press have convincing reasons for speaking up and taking a stand. Because they have cultural influence and power.