However, there is a vast difference between not supporting IE6 and actively fighting against it.
Security experts fight against it. So does Microsoft itself.
Do sites bother with netscape navigator compatibility? I doubt it, and nobody argues about it either, even though there probably are one or two people still using it.
Let your sites break in IE6, and at most leave a note that it was designed for newer browsers, so may not look right on outdated software. Give that same generic note along with the rest of the page to everyone not using the latest browsers, and then you don't have to worry about backwards compatibility.
Too many people use IE6; that's the problem. Companies even still have IE6 on their computers are
policy sometimes. It's easy to say "just don't support it", but that can screw you over when a significant amount of people and organizations still cling to it. Even in September of this year, more people use IE6 than Safari.
Also, that doesn't address the security concerns, or the fact that there's
no good reason to still use the thing except inertia. It's not hard to learn how to use a new browser, and IE6 is slow, doesn't have tabs, doesn't support several web standards/technologies, doesn't render sites correctly, can be crashed with a single copypasted line of HTML/CSS, and lacks modern security features.