In a regular 9-5 job you’re selling your time to an employer
Or, to look at it another way, you are collaborating with a number of colleagues to develop and sell software, and you are all sharing the income. See how that's the same thing, phrased differently? Attitude matters.
You can do whatever you want now. Everything is under your control. It’s not dependent on your boss, co-workers, or other departments. You decide what projects to work on. You decide when you want to work on them. You even decide whether or not you want to get out of bed every day.
You're not dependent on anything - except your customers or clients, your investors, your employees, third parties… the list goes on. Sure, you could choose to stay in bed, or leave for a week and do no work - but you'd have to consider what the implications would be for your services, your family, staff and so on. Sometimes, the illusion of freedom is more dangerous.
You get to put all your time and effort into only things you’re truly passionate about.
Nope - all of the grunt work still has to be done. Need a stupid feature for a large client? You'll probably be doing it. And you'll be doing all of that sysadmin stuff you hate too.
Selling your time for money to an employer will put a cap on the amount of money you can make... You are generating more money for their business than they’re paying you. That’s the only way they can run a profitable business. Which means you’re getting screwed.
It's a trade-off, isn't it? I think we can all accept that the self-employed will keep more of the value they generate. But the other side of the coin is that they're exposed to more risk. Not a bad trade-off, especially if you've got a family.
Most of the software you write at a company doesn’t ever ship.
I can count on one hand the number of features I've ever developed which didn't ship, and quickly. Maybe if you work at a dysfunctional company, this could be the case.
tl;dr: don't take a job at a rubbish company you're not interested in. Enjoy what you do - have you seen what the market is like for "developer time" recently? You can have your pick of companies, developing software for almost any imaginable market, and earn an impressive salary doing it.
Okay, maybe this works for you - and that's great, I'm all behind people finding work that suits their lifestyles. But I've got an awesome 9–5 job, where I am paid very well to work with great people on interesting products. There are a lot of other people in that situation, and I don't think that it's quite a clear-cut as the author makes out.