The big complain I have is they love to keep backward compatibility when they are using a technology they don't have total control over it. It is totally fine for Windows and DX backward compatibility because they have full control over it. They can evolve it without breaking BC. But, they don't own HTML, so HTML always evolves in a way that will break BC. And since they love BC, they don't evolve HTML as trade off. Then, you get this HTML web dev bashing all over the places.
In short, Win8 embraces HTML5 and will screw HTML6 in the future.