I reported them for harassment with the following statement:
The purpose of this group is to review bomb any game that has gay representation. Their discussion threads talk about using other platforms to discriminate against LGBTQ+ communities and individuals to circumvent Steam’s TOS policies. This type of behavior promotes discrimination, review brigading, and toxicity. It is surprising Steam is tolerating such open homophobia on this platform.
Their point is Steam likely doesn’t condone this behavior; they just weren’t aware of it. Reporting it to bring it to their attention will likely get it removed.