TFA headcanon: Brainstorm is a warbuild and he was a Decepticon at first and thus is as huge as them.
(maybe later on, he’d invent a resizing gun that would adjust his height to acceptable autobot standards when he becomes an autobot later on (or become a double-agent for the Decepticons, or something. havent really thought much about this really. ^^;)
Cybertronian Database 
