Is it annoying when people make open-ended posts? Or when you see one do you say, "Oh, must be a newbie to this site, I can forgive them for that"? Should people who make these kinds of posts be removed from amirite?

Nah, they'll figure it out eventually, or just quit posting because they're tired of getting down-voted.

I'm assuming this is in reference to a certain post on the homepage right now.

I just report them for not being something you can agree / disagree with and hope they catch on. For someone to agree / disagree, you can't just ask a ton of questions. You have to state YOUR opinion on it.