When there's a version of IE that runs on OS X (which a huge number of front end devs use as their primary OS), and doesn't have *really sucky* dev tools (F12 is like pulling teeth compared to Chrome's dev tools or Firefox+Firebug), maybe developers will start to get over their instinctive antagonism towards IE. Maybe IE10 can deal with all the features they're using, but supporting it doesn't just mean adding a bunch of -ms prefixes and turning off UA sniffing, it means taking time out of each iteration to test every feature in another browser (with sucky dev tools).

Historically, IE bugs have a strange habit of being incredibly difficult to fix, and often impossible without detracting from the experience for users of other browsers. Whether that applies to IE9/10 or not is moot - the painful memories make us not want to risk it. 

IE9 and IE10 are still way behind other browsers in terms of standards support. (Source: http://html5test.com/results/desktop.html) It's safer just to not bother supporting IE at all. For most people IE support is a necessary evil, but Paydirt decided that didn't apply to them. I applaud them.