What you've identified, I call the 2x2 attack (since it can be imagined as a 2x2 grid), which is:

- Report on stuff that helps the positions you support

- Report on stuff that hurts the positions you don't support

- Don't report on stuff that hurts the positions you support

- Don't report on stuff that helps the positions you don't support

It's one of the many, many, fake news tactics that allows them to manipulate and present a false picture of reality, without having to tell a lie.