The first is probably more because of the fact, that the devs hardly grasp all the consquences that follow their decisions.
I don't know all the P&P-games rule and how they changed over the years, but I guess. Standing half a meter behind an enemie will hardly count as being out of sight with a decent GameMaster, even more to just get another 'surprise' attack. Or at least you will have to make an extremely difficult dice roll, while in this game you don't need to roll anyway. Sneaking is like the armor system and CC, either it works or it does not.
To refer to an old P&P-joke: To backstabb with a ballista just because the rules did not disallow it.
