As an employee of a web development firm, I have to support IE because our clients don't want to arbitrarily exclude some large percentage of the web.
As a person who has a blog, I don't want to exclude people from reading what I write just because I happen to disagree with a user-agent string my server received.
Not to mention, there are at least four versions of IE in the wild, some less bad than others.
Seriously, do you think they are going to change their browser just to use whatever application you got?
People with good browsers get the "HD" version, and anyone else gets the working, slightly less glitzy "SD" version.
It's like people with black and white televisions complaining they can't see their favorite new shows in color. Upgrade your television or stop yelling at it.