I hate to ruin a good Guardian anecdotal narrative, but male happiness has been trending upward for the last 40 years. Females are the ones becoming less happy, for reasons I will leave to the reader to speculate on:

http://www.nytimes.com/images/blogs/freakonomics/posts/HAP23...

As far as why men can't ditch "the baggage" of striving to win in dominance & competence hierarchies, it is because it was necessary for hundreds of thousands of years for a male to achieve reproductive success. And, all else equal, it still is.