It's all an implicit, unspoken (or maybe spoken) agreement. None of them would be in that line of work if they didn't support the agenda, so they're already all on the same page as far as that goes. It's not really a stretch to realize that, say [THING X] happens, and it has to be reported on because it's big news, but maybe it isn't anti-gun enough, or isn't anti-white enough, or maybe with the right slant, [THING X] can be used to further the agenda. So, the intrepid reporter adjusts a few facts, omits others, adds a sentence or two to inject their own personally-endorsed narrative into [THING X], and there it is - kosher news.
People may start out with good intentions - stick to the facts, always get to the truth, and so on. But they're just interns, and as with any intern at any company, they're just doing what they're told, no matter how mundane or tedious: Stand here, do this, hold that, take this thereā¦ So they get in the habit of just following orders.
After while, they either consciously or unconsciously figure out that, because of they system that's in place, only certain approved viewpoints are what make the broadcast or the article or whatever, so they start seeing things through that filter. Whether or not they actually internalize it is one thing, but in either case, they certainly have to become someone who only thinks and speaks in the approved manner.
It's a classic temple/priesthood/cult setup. The MSM (and it's affiliates) is the church, the reporters are the priests, the shit-tier websites and their owners are acolytes, and the rest of the world are potential converts. It's their job to expand the church and bring in as many sheep to the flock as possible.
This is basic stuff. A second of serious contemplation would have given you your answers. This is hardly worth a thread.
QTDDTOT