Why are men lazy?

This is a genetic predisposition that dates back to the tribal emergence of modern humans over Neanderthals, roughly 50,000 years ago. The sexual division of community labor separated men and women into hunters and gatherers. Productivity for a female-gatherer was based on endurance and extended hours of lower-level exertion. A male, however, was expected to hunt, which required extensive/silent waiting/watching, punctuated with relatively brief intervals of extreme exertion. These inherited characteristics remain with us today and are understood by marketing professionals who, for example, design store-layouts that will accommodate males, females or both separately. Men burst into a store, find the first suitable item as quickly as possible, tie it on their cars and leave, whereas women are content to pick through every rack in a store as if it were a field of berries. To a woman, a man who silently watches television whenever he is home from work appears to be "lazy". To a man, a woman is ... well, that is outside the scope of this question.

Most men are lazy because they do not get enough sex!