One could argue that they where and still are the intellectually and socially invested backbone of the community that formed around Overcoming Bias and LessWrong!

That's the argument I wanted to make, so I think I'll steal it. The intellectually and socially invested backbone of the community was and is distinctly right-leaning. Hence, the site is in many ways unwelcoming to people on the political left, much as was earlier claimed that the site is unwelcoming to some on the right.

They will just have to get over that though.

Right. And I think this applies equally to the right-wing readers and commenters who feel the site isn't sufficiently sympathetic to their political views. Obviously I do not think that the political right deserves special treatment on account of somehow being innately more rational than the other tribes.