Here is a post-election argument that McMansions fed into the problem of American pride:
But along with all of the goods we manufactured and skyscrapers we erected, we cultivated immense pride—a pride that overfocused us on the material rather than the spiritual aspects of prosperity (to do for others) and freedom (to live for others) and military might (to defend ourselves and others). When we overtipped the scales and became weighed down with McMansions we neither needed (with our 2.5 children) nor could really afford, when we began to manipulate the stock market, when we began to make war with drones and shrug off human life as “collateral damage” we justified it by saying we were the greatest nation the world had ever seen; exceptional and indispensible.
The typical moral argument against McMansions (see here) doesn’t usually delve into the idea of spiritual sin. Is the main sin that Americans built such homes (degrading the environment as well as relationships with neighbors and communities), that Americans were too proud of such homes (which are intended to impress and opponents say are too garish), or that Americans saw the homes, and by extension the country that made it possible, as something to be idolized?
Thinking beyond McMansions, what homes then are more moral? Tiny houses? Not-So-Big houses? New Urbanist homes and neighborhoods? Green homes?