What you are not getting is that it is not about your opinion, it's about your delivery.
"I think Gary is biased" is a very different comment to "His posts are hateful and biased, it's pathetic".
As I mentioned earlier - You can have any opinion you want on this site - I have certainly always been able to have my say with no issues whatsoever. Having read a handful of your posts just recently, I can say quite honestly that the problem here is largely to do with your attitude, delivery and conspiracy theories about bias and censorship. I don't know if you are aware of my position on such matters, but suffice to say, I don't support censorship in any form (aside from what is unfortunately necessary to keep such a large forum in check, and I feel the mods and owners here, do a great job most of the time. We, as users, also tend to let them know quite vocally if we feel they are doing wrong).
Also, regarding MyBB being a wellspring of racism, etc, as you per your accusation... Well, not that I agree, but you do realise, I'm sure, that you can't have the freedom of expression you expect (demand?), without the existence of material that you object to.