Your arguement is a little flawed, even if you was to gain the injuries on purpose, it is still great cost to raise the skill lvl. Yes you could raise it faster, but you still have to have the gold to buy the scrolls, its not like a self heal has no cost. You also miss the benefit of having that lvl raised, this then allows you to heal not only yourself but also others with higher lvl injures...... something that is currently lacking in game is high lvl healers. Ask yourself why they are lacking...