Because that makes everything better ...

A snippet from an article on browser market share:

Microsoft’s [share of the browser market] has continued to decline, to 66 percent from 72, though it argues that most of that loss has been on computers that don’t readily support Internet Explorer, like those from Apple

So a 6% market loss for IE isn't that bad, because most of that comes from computers that don't run IE (or, put another way, computers that don't run Microsoft Windows). I'm sure they're thrilled with that excuse.