I don't believe you are familiar with this tech then. Asm.js with Emscripten runs at around 50% of native speed on the browser. With C++, this means it is near java or C# equivalency. You don't need an 8 core machine with 16 gb of ram to play this game at all. We achieve getting players to try our game with a single click in a compile-once cross-platform setting. The base code is the same that runs on Android and iOS. Low fragmentation, high yield, instant access. If you can't see the benefits, then you can't see the forest for the trees.

No. X-Box backwards compatibility requires X-Box Live and a Hard drive for more than one reason: there is compatibility information that needs to be downloaded when you actually pop the game in for the first time. Compare it to how Bleem!cast worked. There was no set emulator, but configured data WITH software to enable emulation. Should that data change, the 360 updates it.