We are software developers. We make tools to make life easier for people ("users").
If a user of your software is using IE6, and you refuse to offer that user support until he/she upgrades to a newer web browser, are you making life easier or harder for them?
I'm actually not asking this question rhetorically, believe it or not. It may be that for you to support an older browser takes away too much of your time, keeping you from developing features that would be of greater benefit to the user.
My point is that you need to ask yourself what is best for the user, not whether catering to someone who's using an old version of a piece of software (who isn't?) is somehow beneath you.
