That may sound grand on paper, Old Sport, but that seems more like a "Single target" kinda thing. If you're against a single boss, I would agree. However, when there are multiple enemies breathing down your neck, and you want to make sure your team is safe, what say you then? I find information is power, and I aim to keep as much of that power on our team.

Say you're in a fight, and you have enmity. You're in the black with the four adds around you, and still in the red on the main boss, your focus. Suddenly, you notice that one of your little beasties are now in the red. How strange? You Click on them and notice that the bard had miss clicked and is now attacking the add. This information would not have gotten to you so quickly if not for that "black and Red" indicator. You now inform your teammate of his misstep and you are back on track.

This knowledge would benefit everyone on your team, as well as expand the potential of a tanks skill to micromanage enmity.