Pajiba has a theory abou what makes Michael Bay make these sorts of movies:

Michael Bay has a profoundly tiny dick. The man has a diminutive dangler — what’s known in medical circles as a micro-penis (less than 2.75 inches erect). And rather than seek psychotherapy for his small penis humilation, Mr. Bay deals with his itty-bitty anxieties by hiding behind his work. It’s classic overcompensation; all the symptoms are manifested in his person — long hair, leather jackets, sports cars — but none more evident than his pursuit of aggrandizement in Revenge of the Fallen. His desire to embiggen Transformers II over its predecessor — to make bigger in power, to enlarge our conceptions — is clearly an attempt to conceal his sexual inadequacy.

God, I love reading reviews of bad movies.