In Other Words, Because He's a Typical Establishment Republican

Romney lost because he refused to provide an alternative to any of this for fear of being labelled a warmonger, flint-heart or social reactionary. He refused to engage with any of the issues that made this Presidential election so truly momentous. Up against the bullying of the totalitarian left, he ran for cover. He played safe, and as a result only advertised his own weakness and dishonesty. Well, voters can smell inconsistency from a mile away; they call it untrustworthiness, and they are right. [More]  

Ayup:

So Romney pursued a tepid and uninspiring strategy easy for attack by the left, which conversely played a brilliantly dirty game by ginning up resentment many in the Democrat base feel toward “the rich” in general and Northeast capital investment elites in particular. It also meant Romney ducked addressing red meat visceral issues that would put fire in the belly of supporters—while many felt obliged to hold their noses and vote for him as the "lesser evil," that did not, and could not, translate into the type of enthusiastic commitments needed to win a championship.