There are several members of this forum, myself included, who find your avatar to be particularly sick.
Personally, I don't see the big deal. Given the kind of movies most of us watch and enjoy here, and the images from those movies that appear as avatars, somebody thinks that the ultimate in "particularly sick" is... bad teeth?
But even if you are particularly squicked about bad teeth...
Some of us don't even want to participate in a thread in which you have posted as we do not want to look at it.
... I would say you have the right not to look. I'm surprised you feel you have the right to force someone to change their avatar just because you don't like it. You have the right to ask of course.
You may actually find the board to be more responsive, such as people replying to your posts more often, if you didn't succeed in grossing them out first.
But you aren't speaking for the board. You're speaking for yourself. And, allegedly, "several members of this forum". Even if that is true, that's not "the board". According to the stats I see up top, there are 1930 members of this forum.
On the other hand...
Oh, does someones vagina hurt?
... as insults go, that one makes me go "Huh?"
But then this whole thread is kind of silly. This is where we need John Cleese to step in and stop it on the grounds of excessive silliness.