Why should a person face a gauntlet of incivility and vitriol, one that you liken to a frying pan, to contribute to an open source project?
Code reviews, design reviews, that makes sense. Being referred to someone at a lower paygrade rather than the top tier of kernel devs, sure. These things are stressful but essential. I'd stand to lose considerable self-esteem from them, but there's nothing I can do about that but get better.
But if I went into a code or design review at work and got a Torvalds-style response, I'd be reporting the person to HR and finding a more civil person to work with. If I couldn't work around them and nobody was making them change, I'd find another job. I could try to modify the problematic person's behavior, but that would be stressful and unlikely to work, and I shouldn't have to act as my coworkers' parent.
Garrett found that there was no HR to appeal to, no way to work around Torvalds, and no way to change him. So he did in fact get out of the frying pan. He doesn't deserve to be seared whenever he gets anything done, so he's not tolerating it. Now he's getting the same things done in a way that normal people will be happier with.
This isn't a deficiency on his part. He merely doesn't want to deal with something that normal people shouldn't have to deal with.