Because you're wrong...
The Start Screen is more efficient, it is better suited to an emerging and eventually dominant method of input for PCs - yet it still supports the previous method, arguably better than the old way, too.
We've had this argument half a dozen times in other areas of this thread. It comes down to Microsoft knowing that if they left the option or didn't make it the default, it wouldn't be adopted because people prefer what is comfortable. Like Apple, they've done this "for your own good", because "they know best". The Start Screen is in fact more *flexible*. This is about progress. It is redundant to have both, and the old way is the one that is getting the boot.
The same arguments have happened every time there has been a major change in Windows -
"Why not leave BOTH ways?"
Because that is redundant.
"Wel then, why not make the new way optional, and make the old way the default?"
Because that discourages adoption, and stalls progress.
