Our game is 100% pixel art.  All this feature would do is make each of our pixels contain 4 or 8 pixels each of the exact same color – in short, absolutely no visible difference whatsoever.  Worse, this feature could simply "blur" all of the artwork, giving you a nice blurry screen.

Or are you saying we should add retina display support, and then repaint all of the graphics in the entire game at the higher resolution?  Because that, while utterly impossible in terms of the amount of work required, would actually increase the effective screen resolution.