I think bias is not always the best way to approach a topic when using support material, and it can certainly be avoidable. Bias usually doesn't present the both sides of the topic, giving you only one side of someone's thought to support to a argument. While we all have our opinions, I think bias it can be still be avoided. You can do this by using support materials that are known to be true, such as facts and statistics. To avoid bias it can also be helpful to show both sides of the argument, so that you are still acknowledging the other opinion while still having your own. So in the end, I think bias is usually bad, but can also be avoidable when using the correct support material.
I agree showing both sides of the argument can really help bring your self to an outside view of both viewpoints.