I think a kneejerk reaction to reading something wholly wrong is to assume it doesn't add to the conversation. I think we're all conditioned to see someone we don't agree with as clearly a troll taking the piss, rather than an opportunity to discuss.
There is a rule about upvotes and downvotes in this community here.
There is, currently. It's actually up for a community vote on whether to keep or get rid of that. If you haven't voted, see the pinned post in the community.