Part of the difficulty, in my view, is that we are thinking about this as a high level benevolent debate - in this scientific, clean and clear environment we think of where we can throw out all manner of idea and deconstruct it logically then there is no argument that is off limits.
Let me say straight up, I love that kind of discussion, I often have a good chat with my right/left/feminist/religious etc. close friends about usually off limit topics... I theoretically would want to be able to do that in the broader population and in broader society.
But the older I get, and the more I see where the internet has taken freedom of discourse, the more I believe that most people don't argue and debate like that. With "Fake news" and barmy political ideologies getting airtime and actually GAINING in backing, and with the quality of media dropping more and more every day with the volume of rubbish news getting regurgitated on social media as fact without journalistic standards in place, I'm more seeing that the majority of discourse is headlines and snippets thrown around with awful evidence and logic, people see it, get confirmation bias on it, or think it falls in line with their view, and then they share onwards.
A post/article/clickbait arguing against it, or proving its sources as incorrect is not nearly as shared and not nearly as widely disseminated and then you end up with a debunked viewpoint being spread wider than it ever should have, because there was no curation of the evidence.
The "Bigot Brush" perhaps played a part in stopping ideas being shared around that were fairly out of the normal discussion, though it also repressed peoples ability to discuss and expose their broader ideas that went against the grain too. It played its part in stopping aggressive ideas from circulating to a broad enough audience for it to damage people. (Not all the time of course, but more than it occurred in the past).
Now am I saying that curation and thought policing of ideas is a good thing? No, probably not. In many cases I think the media that aims itself at the soft left issues that have realised they can turn a buck through whipping up a frenzy on inconsequential "SJW" issues are to blame for pushing away a significant portion of the population towards their own barmy news sources, but I also think we are stuck between a rock and a hard place, and neither complete freedom without fear of reprisal, or significant policing/social shaming of ideals is a good place to be - and somehow we have ended up with a fair bit of both.