The question is, was it worth it? Did he get paid enough to feel well compensated for his frustration? If yes, then why all the venting? And if the answer is no:
You should always be ready to walk away from the deal. You don't have to accept unrealistic deadlines. If you choose to accept them, though, you don't have to allow massive spec changes midway. If you choose to allow it, you better make sure the money is good enough to compensate you for the massive horrible burnout you're going to put yourself through. And if you don't -- well, who else is to blame here? When you take a lot of risks, you get burned sooner or later. Don't make bets if you can't afford to lose them.
You should always be ready to walk away from the deal. You don't have to accept unrealistic deadlines. If you choose to accept them, though, you don't have to allow massive spec changes midway. If you choose to allow it, you better make sure the money is good enough to compensate you for the massive horrible burnout you're going to put yourself through. And if you don't -- well, who else is to blame here? When you take a lot of risks, you get burned sooner or later. Don't make bets if you can't afford to lose them.