[Why are the Networks are Backing Bloomberg and All his Ads? Of course the networks continue to back him to keep the goose alive in the race that lays the golden eggs.]
Journalists at the networks think Sanders is too right-wing. They don’t like Bloomberg and never miss an opportunity to hammer away at him.
While I agree with the rest of your post, not so sure I buy that statement. While I don't watch any news other than OAN, I get the impression that even those at MSNBC & CNN are critical of Sanders, because they do not believe he will be President Trump.