Generally speaking, that's the reaction you'll get when you mention Lor'themar. Though he's been leader of the blood elves since The Burning Crusade launched in 2006, barely a word has been heard from him, and few know his history. Indeed, the sindorei themselves have done little since the events involving the Sunwell's restoration. They hardly seem like strong supporters of the Horde at all. Given this, it's almost easy to see where Garrosh's viewpoint regarding the blood elves comes from.
But the very fact that few know of Lor'themar's exploits, that few know of any tales spun from the lands of Quel'Thalas, is a subtle indication of something far deeper that is actually going on in the forests. The blood elves have had to deal with the most crippling blow their society has ever faced, the destruction of the Sunwell, and the decision of how to proceed after the damage was done is something that plagues the Regent Lord to this day.
It's not easy being a leader. It's even more difficult to be a leader in the face of constant adversity and to do so while still retaining what parts of a decent creature you are while you're at it.