Point 1, 3, 4 and 5 boil down to "not OSS". Point 2 is not true, what does the back-end stack have to do with cross browser compatibility? Point 6 isn't true

Point 1, 3, 4 and 5 boil down to "not OSS". Point 2 is not true, what does the back-end stack have to do with cross browser compatibility? Point 6 isn't true either, for the same reason. You can perfectly well use WebGL and other HTML5 tech in a .NET web app. Point 7 doesn't really matter. Microsoft themselves has said they are going for HTML5 not Silverlight.