Not that rogues were one-shot killing anyone, they just killed in stun things that rendered opponent completely harmless (back in original game there was no way to get rid of those stuns for almost every class), but that's not the point.
Point is that you can always choose whenever and whoever you want to fight, and mostly what you give up is just defense (same for rogues), but that is also the thing you need the least with those tactics.
It sucks a little in mass fights, but it's by no way useless, it just requires some skill or brain to do well, unlike brainless stalking. It's almost never fun to search for them anyway, as mostly they can only be revealed when they do mistake.