Posts by people on the ignore list are actually more visible than posts by people who aren't. While their avatars and posts are not shown, the condensed spaces that their posts take up are bright white against the black background. If my objective is to not have to acknowledge the presence of constant spammers and trolls in the forums, having their non-posts show up in such an eye-catching way actually accomplishes the opposite effect.
My first choice would be that their posts not show up on my screen at all, but if such a change is too much work, I would be fine with having their post area at least match the rest of the background (black on black). If their names were hidden as well, that would be amazing.