Daring Fireball does render almost correctly. And why should Gruber care? He makes a living off of his web site alone as it is. Worrying about 4 percent when you're writing for your own site and it's self-sufficient, when worrying about that slim percentage means a lot of pain, isn't exactly a waste of time, but: why bother?
And its not like 'daring fireball' would be all that difficult to make IE render correctly anyways.