I get what you're trying to say but it seems like you're unintentionally moving goalposts all over the place here. You can't have it both ways. Either you feel like MSNBC is the Democratic propaganda to match FOX's Republican propaganda, ie the "other side of the coin" or you feel like they are "centrists". If it is the former, then how can you then call them "lockstep centrists"? If they're on the "other side" then they cant be in the center. On the other hand, if it is the latter, they why are you calling them "lefty" and complaining that they don't sufficiently endorse the most liberal positions? Why would they be "lefty" if they're "lockstep centrists"?
The other thing we need to address is the notion that CNN and MSNBC are equivalent. They aren't. Like I've said, I consume all three channels and there is a vast difference between MSNBC and CNN. MSNBC is certainly geared to favor Democrats, but CNN is much more focused on being moderate/centrist/mainstream, and simply accurate. The Republicans have tried for years to lump the two of them together as "the liberal/lamestream media" and Trump has stepped up these efforts by essentially declaring war on CNN as the "Fake News/Enemy of the people" but that's just a clever tactic on his part to move the Overton window. MSNBC was always seen as the counterpart to FOX by Republicans and CNN was easily recognized as the more centrist of the three. But now by branding CNN as "liberal" and getting people to buy into the notion that they are the same as MSNBC, Trump and the Republicans make FOX seem 1) like an underdog fighting a 2-against-1 battle and 2)more reasonable, in the sense that "its just one side of the same coin" and "both sides are bad" and similar moral equivalence themes. The positions that you are taking here seem to suggest that this strategy is working.
And that is a big part of the problem with the "both sides are bad" narrative. It presupposes that the Republicans and Democrats agendas are morally, economically and socially equivalent in merit and value. They aren't. If they were, then yes a "variety of opinions and choices" would have value, compromise would have value, but as I've said before... there's no "compromising" with someone who wants to add feces to the mashed potatoes "for flavor". FOX is mostly horse manure. A plate of wet horse manure with also some beans and gravy on it isn't "variety", its a plate of manure. I'd rather have a plate of mashed potatoes, sans manure. It's might not be as "diverse", but its at least fit for consumption. FOX just has the beans for the manure juices to bleed all over and ruin it. The contrary voices on FOX are just punching bags for them to mock and beat up on and make them look foolish.
Its easy to conflate "doesn't give Bernie sufficiently favorable coverage" with "lockstep centrist" but they aren't the same thing. Its even easier to conflate "gives Tump negative coverage" with "lefty" but they aren't the same. CNN gives Trump unfavorable coverage because Trump deserves unfavorable coverage. Same for MSNBC. Accurate coverage of Trump is going to be unfavorable because Trump is odious. The reason Bernie doesn't get the coverage that Biden gets on MSNBC is because MSNBC wants the Democrats to win, Bernie isn't a Democrat, and more importantly, they aren't buying that Bernie is the best candidate to win. I expect that if and when Bernie becomes the clear frontrunner, MSNBC will be fawning all over him. With CNN, they are trying to appeal more to moderate/centrist audiences.
