You are self-aware enough to acknowledge you are in a bubble in that respect (as most of us are but not everybody likes to admit); you should consider going a step further and understand that the larger community you talk of ("Conditioning on that type of person, who make up most people on HN, Reddit, and Twitter") is itself a bubble that is perhaps rather more liberal leaning than society as a whole - or at least not as sympathetic to the more activist types being discussed here.

Even if in the long run it turns out your position becomes the mainstream, that isn't necessarily nearly the case now.

This is why your original "elsewhere" is being questioned as it's likely not a representative baseline in that regard.

Whatever HN is, it certainly isn't right-leaning.