Tell me this: If someone's in the (small, obviously) market for a Windows RT device, why would they get anything but the Surface RT?
Every other Windows RT device is built like a cheap piece of shit, with either a crappy screen, plastic body, horrible keyboard dock, or some combination of all those factors. No matter what you say about the Surface RT, at least it has an awesome screen (despite its resolution), incredible build quality, and the type cover is every bit as good as any laptop keyboard.
So even if the Surface RT was selling like hotcakes, why the heck wouldn't the prices of every other Windows RT device on the market drop quickly and substantially? Why would any software changes or anything else make any difference here? It's a clear-cut case where you have one choice that so obviously better than every other choice, so every other choice deserves to fail spectacularly.
Desktop apps on Windows RT simply isn't going to happen. It just isn't. It wouldn't make the device any more compelling, it would just cripple what's already a slow device. You'd have arbitrary and unmanaged background tasks destroying the performance, battery life, and reliability of the device. You'd open it up to malware problems. And from a technical perspective the Store is engineered to work exclusively with modern apps. It's not some generic distribution pipe that could technically send anything along.
