This comes off as petty to me, and a bit stupid. Maybe only 3.7% of his users are IE users because they get a whole lot of attitude when they visit his site?

This comes off as petty to me, and a bit stupid. Maybe only 3.7% of his users are IE users because they get a whole lot of attitude when they visit his site? Or because a lot of IE users either don't have the choice (corporate) or the desire or the skill (grandma) to upgrade their web browsers. Perhaps CEOs of major corporations visit his site every day curious about whether they might deploy his service across their whole company (ok, fantasy), and then leave because he says he doesn't want to support them. Perhaps his business could be 20 times bigger if he wasn't so obsessed with this issue. Perhaps that isn't the case now but it might be down the track. There are lots of great frameworks out there that nearly completely remove the cross platform issues in coding for browsers these days for all but the most unusual requirements. This is not the issue it once was.