I'm just another one of those. You know, those who do things. Things that need to be done by those that do these things in order to do those things that don't do these things themselves. Has the word 'things' lost meaning to you already?
Stormcrack is worse than Lightning Bolt in most situations. 3 Mana for 4 damage and to minions only is paying 1 extra mana overall, 1 extra mana upfront for 1 more damage and reduced target selection. Very disappointing, even for control but decent tool for arena. It works with Flamecannon since 4 damage for 2 mana without the overload is great for tempo and it synergizes with mage for spells.
A side note, I imagine this was for any target at first but Blizzard scrambled to change it since people feared face shaman.
*Edit* When on low health and an empty board, against face decks or perhaps control burst, you cannot play Hallazeal the Ascended and Stormcrack face for the heal, you'd have to hit your own minion as a situational downside.
Man, I think the trauma of rolling low on Crackles actually make me want to run this card instead, haha. This card is in between Lightning Bolt and Lava Burst in terms of cost and damage. Too bad Lava Burst ruins the theme by being overload 2.