I think his issue was with the phrase "Distributing the wealth" and the picture, not the actual math, so saying they think math has a liberal bias isn't exactly true. I do agree, however, with the guy in the video that this is a terrible "conspiracy."
Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own - Bertrand Russell