in democratic western countries, its pretty nice to have a state-owned tv/radio station. just because they are generally a tad boring and conservative (not in the right wing sense, just in the keep it simple way).
and they get mad shit for every mistake they make and the state is not controlling them. they dont have to fight for audiences, so they dont invent shit or downright lie about something.
and the privately owned news stations know that people trust the state owned news and just add a little celebrity stuff or baby-seal crap every here. they know that if one such story comes up, noone will probably watch their news anymore because of an unbiased and legit alternative.
i dont know a lot about the US media market, but i am pretty sure that there are no state-owned tv stations that do not have to fight for audience or sponsorships.