It bugs me that the 4HWW advocates finding a "muse" to earn your living instead of creating something of actual value. That book explains why there are so many fitness ebooks written by The Situation and friends.
That being said, "ask for forgiveness, not permission" is great advice. It changes the way you approach problems. Anything that gets you to question the way you think is gold. In that way, the book is awesome.
Not to bring up this old discussion again, but all of these business provide 'value.' This is capitalism; if someone pays for it, they find it valuable. You're creating some sort of secondary game where certain businesses are below you, Tim's just trying to tell everyone to play the real game.
I expect I could make some money selling magic "quantum" stickers that enhance the sound of an audio system, making them for pennies and selling for hundreds of dollars. But that would be wrong.
I'm not saying writing and selling ebooks is an inferior business. I've bought a lot of great ebooks. But if you read the 4HWW closely, he recommends rehashing content from other sources and claims by doing so it justifies you to call yourself an expert. That's disingenuous at best and plagiarism at worst.
That being said, "ask for forgiveness, not permission" is great advice. It changes the way you approach problems. Anything that gets you to question the way you think is gold. In that way, the book is awesome.