What makes you say that? These threads are always filled with unrealistic expectations, but there is a precedent for the solution I provided since there is already a history of separating a spec with identity issues into two unique specs - Feral Druid becoming Feral and Guardian.
While I agree there's very little chance it happens, it certainly isn't outside the realm of possibility, seeing as it's basically already happened, and seeing how it would be an intelligent way to being to address everyone's issues with current Shadow Priest.
Don't people like you get sick of unnecessarily shitting on people's thoughts and opinions in these kinds of threads? Just move along man, if you don't want to participate in what can be some really cool and thoughtful discussion, then go flame people on Reddit or something.