I know that testing on IE is possible, but there's more to it than that. If I'm just going to test my stuff on IE every now and then to make sure it works, I'm not going to focus on, or experiment with cool new features the IE teams adds, because the only time I use the browser is when I boot up my IE testing VM.
If IE ran natively on Mac and/or Linux, for instance, I would spend a lot more time actually using it, not just clicking around my app to make sure it isn't broken before a release.
I know that testing on IE is possible, but there's more to it than that. If I'm just going to test my stuff on IE every now and then to make sure it works, I'm not going to focus on, or experiment with cool new features the IE teams adds, because the only time I use the browser is when I boot up my IE testing VM.
If IE ran natively on Mac and/or Linux, for instance, I would spend a lot more time actually using it, not just clicking around my app to make sure it isn't broken before a release.