I'm always surprised by how offended people get by things I write. It seems totally unpredictable. I didn't expect people to be so offended by this one. In fact, I thought I was saying something rather smarmily ingratiating, if anything: that the famous startup founders you keep reading about in the press are not that different from you, but that they just have, in effect, a healthier work environment. See the last paragraph.
And yet somehow that message has gotten completely twisted around. It's as if people wanted to misunderstand this essay.
I've been mulling over why this happens, and one reason is certainly the one you suggest. I try to cut every unnecessary word, and I don't say things unless I'm pretty sure of them. The result sounds arrogant, because it doesn't have any of the hedging people usually surround ideas with to make them palatable.
But there's no alternative. People won't read essays if they're too long. If you want to get a lot of ideas into an essay short enough to read, you have to be so curt you sound arrogant.