I don't think most people are biased, I just think they might have a strong opinion about something. How do you define bias? I define it as a unjustified preference toward something. For instance, if I preferred the PS3 over all the other next-gen systems, but couldn't tell you why, would I be biased? Yes. Is that the case? No, not if you've read any of my posts. There's nothing wrong with letting past experience influence your taste/beleifs/actions. It's when you only let your past experience influence them, and refuse to try to see the other side of the argument that it starts to cross the line into bias.
If you think I'm biased, then you're mistaken. I have legitimate reasons, past experience, along with personal preferences that compose my opinion. How I choose to express those opinions is my choice, and clearly, some people can't handle that. In fact, before any of the systems came out, beleive it or not, I was most excited for the Wii. I thought it would have a ton of potential and change gaming forever. In reality, after playing it for a week I realized that it was just a gimmick that became more annoying and tiresome than anything else. So you can call me biased all you want, but if that were true, I'd still be playing my Wii, trying to convince myself and everyone else that I'm having fun playing the greatest system ever made.