This.
When a sorcerer casts force lightning, it's purple lightning. When they whirlwind, it's purple lightning. When they cast lightning... you guessed it. Purple lightning. Electrocute? Purple lightning. Shock? Itty bitty purple lightning. So, when you see a sorcerer casting the spell(s) you're calling "purple lightning," and you think, "That's all they use!" Well, you're right.
Learn your enemy, or troll the boards and shout "OP!" I suppose the choice is yours.
Now, if only those damn Jedi would cut out that rock throwing crap. Gonna put an eye out.