It's all an act on Sherman's part to draw attention to himself.
He's stuck in Seattle, if he doesn't draw attention to himself he would be a forgotten man.
He may be coming off as an ass....but EVERYBODY is talking about him.
He's gone from a no name to a big name, not because of his play on the field, but because of his antics in the media.
He's gone from someone only close followers of football (and Seattle fans) knew about, to becoming well known, even by casual fans.