Tao has gotten a lot more public media attention for the most part (Netflix, shows, TV, news, etc.) than any of the others which remain more niche. I'd guess as a result the audiences of the others are better selected to lean more high quality.
Also there's plenty of shows and news about MU, SSC etc. I'm also surprised that Tao's rather specifically niche blog attracts such comments. Is it possible that the other blogs are just better moderated and Professor Tao doesn't need or care to?