You're kidding right? You must live in the Bay Area. There exists these other continents named South America, Africa and Asia. I know I sound crazy right now but people in those mythical lands I just mentioned don't have the latest and greatest computers, or anything remotely close.
Try closing your eyes for a minute and imagine a land without latte art, Apple products and toques. It'll blow your mind.
I don't think these people are stuck with IE6 either. I'm pulling this out of my ass but my belief is that IE6/7 users are people who don't own the machine, in other words employees stuck with corporate system[1]. Other than that you can just install and run firefox or chrome on old machines[2].
[1] I've seen it in national offices were they could only use a verified systems that were implemented by some company in the win95 days so they can't upgrade. In other companies they bought brand new lenovo desktops and scrapped vista to put xp+office2k3 for IT support and compatibility reasons.
[2] I run a 2006 laptop as my main one (tpad x60s), and often use a 2005 x41 on the go with no issues.
Try closing your eyes for a minute and imagine a land without latte art, Apple products and toques. It'll blow your mind.