I disagree. Fear is one of the two major forces at work in a startup (the other is faith).
There are legitimate fears--these are the risks. Fear that you'll run out of money. Fear that you've picked the wrong people to work with. Fear that you'll be beat to market. If you don't have some measure of fear, you're ignoring risks, which makes your failure that much more likely.
You definitely need a constant drive, but I don't think it has to be fear.
The fear you should have is not being able to make rent or buy food. You should fear having to go back to your cubicle job or the lecture hall at school. Know that a startup lifestyle is for you, and fear going back to the life you didn't want. Fear these and that will keep you reaching to succeed.
He speaks humorously with a good point (Go do it!). I don't think someone just starting up should be in the same state of confidence as he is, but his attitude towards working hard is noteworthy. He can speak whatever he wants, how he wants. That's a nice freedom. Picking up his book on Amazon with Founders at Work. Even if I don't learn something from him, I'll at least be amused, http://www.amazon.com/gp/offer-listing/0091912652/ref=dp_olp_2/103-9496918-3879027
An update on the book. I'm almost done reading it, and I would like to say that it's a really amusing book (not the Anthony Robbins type). Some take aways (I'm not saying I agree with them all. I could agree, but I'm just saying I'm not saying that.):
1) You gotta really really want to make money, more than you want to be happy if needs be. Be compulsively determined.
2) Don't try to cheat the IRS.
3) Delegate. Hire smarter people than you, and pay them very well, but keep ownership.
4) Get rich. Give it away.
5) Timing is very important, more than talent?
6) Execution is more important than the idea. Just go do it.
7) Self-belief is priceless. Confront doubts for facts.
Those fears can be legitimate, but I don't think they're favorable, because there are alternative and positive forms of motivation to deal with those situations. Fear also overrides logical thinking, which can't be good for business.
There are legitimate fears--these are the risks. Fear that you'll run out of money. Fear that you've picked the wrong people to work with. Fear that you'll be beat to market. If you don't have some measure of fear, you're ignoring risks, which makes your failure that much more likely.