Great read. No surprise that the author reads Pratchett.
I've been writing software for nearly 30 years and he's preaching the gospel. It's clownfuckery all the way up. I will only add that running your own consultancy can be fun, but it's not going to dissolve his ennui.
I've been down this road. Sure being a consultant, gets you out of the day to day political shitstorm at any given company, but the clients still want software churned out at rate that is incompatible with quality. Plus you have the added bonus of not knowing if you'll have a job in 3 weeks.
Is it worth it? Yes. Do you make more money? Sometimes. Is it easier or less stressful? Not by a long shot.
I wish them the best of luck.