You can do what your describing with a lot of devices, not just an iPad.
But that's not the point.
The point is POTN has to draw a line somewhere, and line is currently drawn at devices who's main purpose is use as photographic tools.
While you maybe able to use the iPad as a photographic tool, it is not the main purpose it was designed for, nor is it a major function of its design.
Of course you could make the exact same argument about the Mac Mini (not designed primarily for use as a photographic tool), but you don't. This can only mean a.) the collective position of the mods is anti-iPad; or b.) devices like these, useful as they may be for photography, are not welcome for trading at POTN because doing so would open the proverbial marketplace floodgates.
(b) makes complete sense and I'd totally respect that position. If it's (a) ... well, I hope it's not (a) 






