I think he did a pretty good job explaining why he made the choice to drop support for IE in TFA.
While I admit, IE really blows, and I hate developing for it, it's really not that bad. It's manageable if you test on it often, which author failed to do. Is it hard to make a 9 cell table to get rounded corners? Or how about learning "hasLayout" which fixes virtually every IE6+ css rendering bug?
I agree that developing for IE isn't the worst thing ever, but it's certainly not fun. I have to side with Marco on this, if I were to build a site just for fun, I'd probably never look at it in IE.