It's because they are not journalist, they are entertainers posing on a infotainment "news" station. American politics is a lot like American Football. you have fans supporting two different teams and the fans just use talking points they hear ring leaders on shows like this use in daily conversations with others on their "team" and against those that are on the other "team".
Most Americans don't even register any more when hosts on shows say "we" on these networks because those tuning in already assume depending on what channel you are watching they are rooting for one team or another, MSNBC = Dems, Fox = Repubs, CNN = Tries to act like they are neutral, but in the end it all comes down to sensationalism reporting where truth takes a backseat to good tv drama that will keep people tuned in so that the networks can keep viewers glued while they go to commercial break so the network can make money. No such thing as true journalism on TV in America anymore, anyone that tries that will be restricted access to politicians and won't have jobs because the networks won't like how they don't adopt the us vs. them mentality that is the culture today.