A tethered virtual monitor wouldn't be a PC, it'd be a PC peripheral. Cook wanted a PC platform and app store he could call his own, so we got this 1.5 pound strap-on facial PC instead of a really nice virtual display.

Also, it doesn't make the best virtual monitor anyway, as the display fidelity is about half-Retina, so all the pixels really stick out compared to every other display Apple's shipped in recent memory. A 1998 Powerbook has crisper text.