Actually on reviewing the thread, you haven't really. Your assessment that dungeons are lesser versions of raids, while factually true, is a bit goading, as is the toolbox comment, but you've been on the receiving end of some undeserved punishment in this thread, imo.
And you are correct that it is a damage increase to apply expose armor, especially if it is glyphed, depending on your raid comp, and often in dungeons. While damage doesn't matter much on "heroic" 5 mans, it's still correct play to press expose armor, especially if the rest of the team is not smart enough to do so. I'm even finding several situations in a raid where it is good to do so- for instance, pillars on Elegon, the front leg of Garalon (the prot warrior is in the back there, and he's arms), the Strength of the Emperor, the Courage of the Emperor, any stone dog I'm on and the prot warrior isn't (aka, when our pally has them), and the mage when he gets MCed on the first boss of HoF because ha-ha I totally got you mage! I don't ALWAYS press these buttons (I don't on courage because it dies so fast and is mostly caster dps), but the option is there when I remember it, and unlike cata and the five minute fairy fire, it's not free to have the resto druid do so like before.