This is probably just a whiny complaint of well-known and long running issues. Indeed for a long time most blog sites (not to mention most twitterspheres and Instogram Idiotspheres) have been mono-partisan in those who participate in their discussions/debates. This has been true for a long time for most sites in the Econoblogosphere, including this site, which clearly tilts “left,” even though we have always been open to comments from a wide variety of views.
I have in mind here a particular blog site that I respect and have been spending a lot of time and attention at for some time. It is Econobrowser, initially set up by Jim Hamilton, now at UCSD, and a leading time-series econometrician, long viewed as a nonpartisan technocrat. Some years ago he brought in Menizie Chinn of UW-Madison as a co-blogger, with Menzie becoming the main poster recently, with Jim H only rarely now posting or commenting on anything.
This site has been for some time now one of the few among higher level economics sites where people from different partisan positions have been regularly posting, reasonably intelligently. It has been for some time tilting “left,” as Mr. Apolitical Jim H rarely posts, with Menzie Chinn dominating the site. He served for both both Clinton and G.W. Bush as staffer on the CEA, giving him a cred cover of bipartisanship, although since Trump came in he has clearly been negative on Trump.