If you're working for money you're not retired. There's even a whole spiel in the link above about how they tried to become property developers which failed when the market collapsed, which is actually a lot of work.
I'd buy semi-retired. Or he works part-time. But retired has a very specific meaning that he is ignoring. He just seems to be confusing 'I enjoy my new job' with 'I don't work' just because he didn't like working 9-5 as a programmer or whatever it was he did.
I'm a fan of the MMM blog because it describes an attainable alternative lifestyle for talented people who aren't already wealthy. It may not be a lifestyle that many people want, but at least it's a change from the high college debt, two income trap, expensive city lifestyle that seems to be the norm for lots of young families.
I don't aspire to live on 20K per year, but thinking about how lowering your personal "burn rate" can give you more freedom in your life is a great mental exercise.