I think bias is an unavoidable thing in writing, and I don't think it's always a bad thing either. The book mentions how the question of bias is not if a person has it, but if they alter facts and promote information in order to get their point across. That's when it becomes an issue. I think it all depends on how someone delivers their bias, and if they're being respectful as they do it. It's a good sign if they mention other viewpoints besides their own, to show that they acknowledge that their viewpoint isn't the only one that's out there.
I agree that bias is an unavoidable characteristic that people possess and that having bias isn't necessarily the problem. I also agree that being respectful in acknowledging other viewpoints is a good sign that a person's bias is not being the only thing presented.