You clearly understand what's going on. It seems the facts are straight. Knowing that you can't change his mind, opinion or how he communicates them, what exactly do you think should be done?
A.) Let it bother you
B.) Chalk it up to a difference of opinion
C.) Ban Him
D.) Decapitate him
E.) Disregard his posts, encourage others to do the same and provide them with plenty of details as to why your opinions are valid and his are not.
I know what I'd pick.