Dark Elves were not difficult to use in 6th. They were actually remarkably easy, despite the constant whining of the Druchiiiiiiiiiiiiiii.net crew, but they only had one or two real builds.
Ogres are the perfect example of a failed concept. GW obvious envisioned a horde of fatties runnign the board, bull charging and chopping the enemy to bits. They then built in limiting factors to prevent this concept from sweeping too many people straight off the board.
Unfortunately, even if a unit gets into contact with the enemy, they are not generally good enough to sweep 50% of units off. Add their horrid resilience, complete inability to deal with large flying monsters (other than the Tyrant with a tenderiser - who cannot get in contact with him!) and the lack of support models you have a list that is broken. Only as a MSU army does it stand a chance, and even then it stumbles. Great models though.
Phil