I think Robin's concern is that people are reluctant to admit when they're uncertain, so they'll state opinions that they aren't confident in. Perhaps rather than saying IAWYC, it would make more sense for people to say IDDWYC (I Don't Disagree With Your Conclusion)? Not disagreeing means either agreeing or being unsure, without saying which. That would serve to clarify the difference between nitpicking and dissent, but leave a better line of retreat for people who flip from unsure to disagree.