Sure, he and his wife clearly worked for what they have. Doesn't mean there isn't survivor bias (luck) and privilege at work. For example, anybody who can pay for their own college from jobs they worked as a teenager is privileged.

Take a look at his own story: http://www.mrmoneymustache.com/2011/04/08/mr-money-mustaches...

He doesn't say he grew up in a family without a ton of money. He grew up in a frugal family. In Canada, with a number of social support systems that simply don't exist elsewhere. He could attend a local University on his teenager job savings and had a good job waiting for him upon graduation. He and his wife found a fixer-upper they could afford to fix up. And so on. These aren't things that happen to or for most people. The suggestion that his experience generalizes is terrible.