I'm so conflicted about FW-- on the one hand, they've made it! And I think they have credibility as advocates of frugality, mindfulness, etc. But as many people here have pointed out, they don't really "own" their story and actually seem to spread misinformation and half-truths about their finances (e.g., that they were normal, middle-class folks working uninteresting, middle-of-the-road non-profit jobs until they were able to move to the woods). It would have been interesting to hear how they managed their careers and negotiated their job offers and salary increases and navigated tricky office politics. Instead "Frugality" is being peddled as a platitude, a solution to everything.
But like others have said, it's dishonest and self-promoting to have a personal finance blog with evasive language about being middle-class when they probably make $400-500k/yr, and then write a memoir that sells people the dream of financial independence through "simple living" instead of grappling with the discomfort of owning your own finances. But their blog/book, their decisions I suppose.