That is broadly correct, though not all of them are equally biased. However, journalistic objectivity [1] is something we could demand them to strive for. I'm not sure if the press have always been like this.
> Likewise, it’s not particularly noteworthy that WSJ and Fox News have a conservative bias.
Most of the US mainstream outlets are biased in a particular direction. I've said the before here, but you can see that by taking any reasonable list of major outlets [1], and checking their biases [2][3].
> If we are to get up in arms about something, it should be because they are being deceptive (or worse, publishing false information), not because they are merely biased.
Paltering is also a form of deception, and you could argue that it is quite pervasive and pernicious. I think Mother Jones, and many other outlets, are guilty of that.
[1]: https://en.wikipedia.org/wiki/Journalistic_objectivity
[2]: e.g. https://en.wikipedia.org/wiki/News_media_in_the_United_State...