I know the OP said this was a rant and there is no need to reply, but I will anyway.

Know that not all of us are like this, OP. I tend to restrict my tips to mechanics, and only if I know someone is new or we wipe. People tend to be open to advice about mechanics when they say they are new or when the group dies. Otherwise, I keep to myself or engage in idle conversation if someone else is. If I feel the need to address a faulty dps rotation in a high level dungeon, and I haven't since the old AK NM days, there's a good chance that I should just leave anyway rather than risk getting into a shouting match over what needs to be done.