Keep in mind that Microsoft spent 2 generations before converging on the current strategy: 'non-Pro' Surfaces 1 and 2 were ARM-powered Windows RT devices that could only run Windows Store apps (similar to iPad). When noone seemed to want that, Microsoft went out and made 'non-Pro' Surface 3 just a cheaper, slimmer, lower-powered device, running the same version of Windows as its bigger sibling; also non-Pro was released after the Pro and just after the newest Intel Atom chip: http://ark.intel.com/products/85475/Intel-Atom-x7-Z8700-Proc...
I actually expected the iPad Pro to support OS X apps; maybe via being powered by a new Apple Ax frankenchip that runs iOS ARM as well as x86 code (another payoff from the investment to custom chip design) and/or by requiring to recompile with the latest XCode for the App Store (a payoff from the long investment in LLVM).
Maybe next year.