Exactly. I want to control what I see and what I don't see. I don't need Microsoft Bob to not show me emails "LIKE this one" (or Google's less-annoying equivalent). I know what I want: I want to never see another email from specific blacklisted individuals or domains ever again. I don't need a "Just Do What You Think I Mean" button. I know what I mean.
You sound like a Diaspora kinda guy.
FWIW, Temper, I do use my spam button when it's appropriate, i.e. on spambots. It's pretty safe to use it in that fashion. This was sent by a real person and was directed specifically to me, albeit unwanted and inappropriately. It's not spam. It's more like trolling, or online stalking. A filter is the correct tool for that.