I see a great deal of writing being wasted on the idea that the whole of the content should strive to be as objective as possible. Everything from journalism to philosophy to teaching should be objective. Of course that sounds ideal, but it isn’t actually possible.
To truly be objective would be to say nothing at all. As long as every article, lesson, book, and news piece is written for a purpose then it is biased just in the basis that it was written. We as people are very opinionated. Even if we know practically nothing on a subject, we still have an opinion on it.
You can say that a news article can show no clear bias towards one side or another, but that’s only what you see. Say we have two events, A and B. News agencies can choose to cover event A but not B and immediately fail at being objective by ignoring the second event. They are showing bias towards the first subject but not the other. This is part of the reason why many events are not displayed in the news even though having a great deal of importance. And since every single topic out there cannot be covered in detail, it shall remain biased.
This model can be applied to other subjects. The point is not to strive for objectiveness, but to admit your biases. Know your biases and have a clear understanding of what they are. Something that is a fact to you will always be a lie to another.