I am one of the complaints you know about.
I most certainly noticed.
The effect is noticable by others. How much energy have I spent stating my opinion on the politics recently instead of answering questions? Can you honestly say that I (right in this post) am helping people learn as effectively as I could if I was not discussing politics?
Perhaps you think that having me spend time thinking about how to actually get feedback from some of the people who dislike me is more helpful than having me spend time on a thoughtful post on how thinking in terms of completed transactions leads to more robust infrastructures. Well I disagree! Personally I think more people would benefit from seeing my informed opinions on how to write robust code than benefit from knowing that I think mean people suck!
I have decided to stick it out simply because on a personal level I have so much support. But I have had conversations with others who have noticed, and I can definitely tell you that there has indeed been an effect. Both in terms of who does (and does not) contribute and the value of their (and my) contributions. You are kidding yourself if you think otherwise.
Now what kinds of fixes are possible? Here are a few ideas:
They range from trivial in their impact on the culture here, to drastic. They range IMHO from quite good to extremely bad ideas. (And that is how I ordered them.) I put them out there so that people can have a somewhat richer discussion than just, "Something needs to be done!" "I don't want my freedom to be limited!"
And yes, I listed your response at the bottom of the list for a very specific reason. Because there has been an impact, not only do I see that in my case, but I have received an earful from a number of people. One of whom made public comment: RE (3): Goodbye!.
In short, if you think that the technical contributions that I am capable of making matter (and some here most definitely do) then there is a problem and it does no good to say otherwise. If you do not think that the technical contributions that I am capable of matter, or you have strongly negative opinions about how I make them, well you know how to chatter at me so please do.
In reply to RE (2): Limit on voting down a person (Run in circles, scream and shout)