There are a lot more useless (or at least, situational) skills than masterful strategies. It's true that I do not take this skill over masterful tactics and several others, but on the other hand, masterful strategies artifcats are, in my experience, quite common and randomly available quite early in the campaign, at the time where you get the most of it (eg. you don't have the overpowered units/spells combos that will allow you to win battles with 0 losses - which render this skill obsolete), and, even if it is for a temporary time, it has its role, and can save time, food and money in the early game when those resource are scarce.
It could certainly be better, but imho, the problem with the skill is not the cut to troop loss, it is the morale boost, because the unit stack morale concept doesn't work well in practice : it is trivial to keep it maxxed out if you win your battles, and if you loose, well, you'll have muche more to worry about that unit morale. A more relevant morale system will make it a more desirable skill, imho.