No one is ignoring the issues. The author was never saying their wasn't security issues. He even states some of the steps that the Chrome team and the Firefox team (who are working together on this) are taking to make WebGL more secure.
The point is, Microsoft will have to do that exact same things to secure 3D in Silverlight 5. Why not use that work for WebGL in IE10?
The author also point it out that microsoft is in one of the best position to help secure WebGL by putting pressure on Driver vendors and using their knowldege of the OS. In fact Gregg in the post talks about the reset ability in windows which lets browser reset GPU when they see browser operation blocking them for too long. This is a feature that he claims is only well supported on Windows. And that Microsoft could work with GPU vendors to make that even better on Windows.
The point is, Microsoft will have to do that exact same things to secure 3D in Silverlight 5. Why not use that work for WebGL in IE10?
The author also point it out that microsoft is in one of the best position to help secure WebGL by putting pressure on Driver vendors and using their knowldege of the OS. In fact Gregg in the post talks about the reset ability in windows which lets browser reset GPU when they see browser operation blocking them for too long. This is a feature that he claims is only well supported on Windows. And that Microsoft could work with GPU vendors to make that even better on Windows.