I agree with your conclusion, but I don't agree that it's a straw man. There remains a fairly large subset of people who are "fine" with having LGBTQ coworkers,

I agree with your conclusion, but I don't agree that it's a straw man. There remains a fairly large subset of people who are "fine" with having LGBTQ coworkers, but if those coworkers regularly talk about their personal lives to the same degree that non-LGBTQ coworkers regularly talk about theirs, it's seen as "pushing it in our faces." On an earlier thread about Basecamp, I suggested that if the real goal is to keep conversations in the office civil and focused on work, the policy should be "keep conversations in the office civil and focused on work." You can politely shut down acrimonious debate in your Slack not because it's "political," but because it's acrimonious, and you're not sending a message that "political" discussions that really do have a bearing on your workplace culture are off-limits even if they're conducted respectfully. That's where Basecamp dropped the ball. (And let the ball roll under the couch and then set the couch on fire.)