In U5 THF was nerfed to disallow glancing blows when moving. The conjecture here is well known that it was due to "twitch" a moving combat style where people were interrupting their swing animation in order to increase attack speed a small amount. Disallowing glances while moving for everyone made it so that "twitch" was less DPS than standing still and swinging.
With the advent of SWF, THF is losing ground in what it is supposed to be good at. AOE DPS. If I have to move to get into position, the glances will not proc and I lose DPS -vs- being nailed to the ground, and being nailed to the ground in EE quests means suffering an accute bout of SMDS, Sudden Melee Death Syndrome.
Time to un-nerf THF. Let this combat style keep its niche at being best at AOE melee DPS.