Because no one treats them as such. Fox has always been treated as partisan, and the Journal is also seen as such. Even conservatives are more willing to admit to those than liberals are to admit the NY Times or Washington Post or the major network news shows are liberal. It's not like Republicans vs Democrats, or BLM vs the KKK, it's the police vs BLM, except the police are explicitly anti-black as a matter of policy, and 90% of them admit to being members of the Klan.

You, yourself, have repeatedly demonstrated ignorance of American idioms & generally accepted perceptions. You hear the names of a few major sources, and disingenuously act as if there is some sort of parity there, when Shapiro had to prove himself with alternative media sources before moving into the ranks, whereas until the internet came along, he would never have got a job at a major television network or other widely available media outlet. For decades the left had a monopoly with the network news and major newspapers, which has only increased with the consolidation of media companies. And beyond the newsmedia is the entertainment media. What is the conservative equivalent of Disney, which can buy up intellectual properties created by left wingers decades ago and say "No, not liberal enough for us, let's make them full bore SJW!"

It's exactly the power dynamic leftists describe when trying to get around the fact that every minority group out there has legal equality.