What's the evidence that causes you to believe that there is an "ideological monoculture"[1] here? I don't know how close to a majority it is, but I'd guess there are many people that would agree with you. I for example 'vouched' for your top comment in this thread, since I thought it was wrongly flagged. But I cringed when I saw your 'Weimerica', because that's just not a useful means of discourse, and will cause people to dismiss your earlier (worthwhile) content.
I'd guess that Dan's response to you came from the same sentiment: you started well, but then veered off into "sheeple" territory[2]. Consider: is he more likely to offer corrective advice on "tone" to people with ideas he wants to see more of, or to those whose ideas themselves are unwelcome? Rather than concluding that your ideas aren't welcome here, consider that the problem might simply be the tone.
[1] Speaking of monoculture, did you know that Dan isn't American? Happy Thanksgiving, Dan!
[2] Regardless of the aptness of the term, I find "sheeple" a reliable indicator of a failed argument.