As for concealments, i agree, question is, isn't the assassin better at this? I see in WZs ridiculously high numbers of them, while Concealment ops? 14ppl out of 800 ... And Lethality ... well noone play them (with a few exceptions) because of bad design.
Thing is, if you play Lethality, you're just hurting your team, because of looong, looong duration of dots (preventing any CC), which is (as the game is now) major problem (besides other purely technical problems - bad design)
You could say assassins are better at it and a 1 off for them is also a 1 off from your team as you are busy and could have been another healer.
That's what sucks. Not that DPS operative is not without it's uses, but there is someone out there that could do it better, and the healing tree is on a much higher level in value.