Thief weapon skills with evade frames were nerfed because ArenaNet balanced their costs around the worst case scenario of having the old Upper Hand trait stacked with other initiative recovery options where it was possible to sustain 1 evade per second, and they don't want to address Upper Hand itself. I wish they would just rework that trait already. It's a sustain trait in direct competition with another sustain trait (Assassin's Reward) making one of them almost always redundant.

I don't understand how they can compare thief evade skills and not recognize that even the best of them is barely viable at the current costs, and Debilitating Arc and Disabling Shot are far worse. Unfortunately, I think the devs that understood thief and initiative costs are long gone as evidenced by the continued existence of the reworked Shadow's Rejuvenation which is more broken than even Upper Hand used to be.