As a Sader, I see both sides of the argument. If you're choosing priest, you should expect to be healing. that's just common knowledge. If im in the face of a boss, I cant be expected to be looking around the field for healing orbs that constantly get dropped next to the priest (who is usually 10 meters away and behind me). Melee classes need an extra helping hand as we are always right in the action and not always eyeing our HP and especially eyeing the surrounding area when the threat is literally on top of you. Throw some orbs where your dungeon mates are. On the other hand, we should all be keeping a watchful eye if we have a healer in the group. Know when to retreat, know where healers are along with the boss, and assess what kind of healer you have (i.e. if it's a dps healer or someone throwing orbs only where they are at, be wary of where to run to, if a dedicated healer, try not to run out of mass heal, etc). Priests should be expected to heal the less attentive inherently, whereas spa should be expected to pay more attention.