You are missing the point....every fighter or barb who cares about there dps will switch to THF, why would they not? They can put more build pts in int or con and limit the weapons they need. So how does that encourage variety in builds?
As for monks, rangers and to some degree rogue all who will most likely not switch form twf because it is how their class is designed. So this is just a nerf bat for classes who are NOT overpowered and in the monks case, may already BE underpowered.
So your DDO will be filled with pure 20 barbs and fighters swinging away with great axes breaking up CC and yelling for heals.....sounds like fun