Piling on that Eva is bad for arena, but ok for duel/TW.
The logic being that in arena, you normally don't have the time to make that investment in gear/kp effective, and need to be piling on the dps as fast as possible. You may never even be attacked or may be saved for last (I often am) nullifying the use of Eva other than AoE's.
In a duel, I've won vs melee def/dps via my evade quite a bit. It depends, obviously. Accuracy is pretty low priority for most people.
In TW it's rare to attract much sustained attention since it's usually pile-on and attract no attention, or get ganked and die, in which case crit or eva is moot. Eva can help, but neither focus is all that important, IMO.