I take it you have never actually tanked.. Besides, relying on someone else is never a good idea.. Like healers, tanks have enough to worry about.. Not to mention we can only do so much..
So here is a thought.. Roll a tank before you tell tanks what to do..
My tank isn't yet level 50 so I can't speak with certainty.
But I've done almost all endgame content with a sage healer and don't find myself needing force wave very much. When I do HM Ops and HM FPs with my guildies I seldom pull aggro. If I do I usually run past the tank and I'm fine.
On the other hand, when I pug HM FPs I tend to pull aggro frequently.
This may be a failure in group coordination, a failure in the dps of handling the adds or a failure in the tank to handle aggro. Since it hardly ever
happens when I'm running with one of my guild tanks, I tend to lean in the direction of tank skill.