yea cuz hes gonna go around res-ing lvl 80 people for fun.... -_-
i think its useful, but it takes away from your other masteries.
for example force is useful when you're burnt, poisoned, etc in some quests.
theres a force skill that heals you, not the one where you heal youself but the one where you can select a target and the base healing for lvl 1 book 1 is up to around 370 hp which is amazing using it on yourself, though it takes like 2 seconds longer than the self heal, great way to save pots while consuming some mp (i think its like 72 mp to use it)
the harmony therapy is beast for thiefs wanting to teleport to the thief town cuz if you use it the NPC's cant hit your camel, horse, bull, etc. and you get healed X0% faster.
i personally dont like res, if you die youre an idiot LOL. shouldnt be fighting level 42 mobs at 35

but if you have force might as well get it.
vital spots good i suppose.
personally i wouldnt get force, i can afford not having it.