I want to plot a numpy 2d-array (i.e. an image), in the simplest way possible, with NO axes, whitespace, or any such thing. This should be the SIMPLEST use-case, and yet....It seems to be really hard. The PIL show() method for Image, does just that, but the documentation says it's inneficient and actually saves the image in a temporary file and then calls unix 'xv' utility (besides, the documentation states show() was made for debugging purposes).

Why is there no simple way in matplotlib to plot a matrix of values (i.e. image), with no bells and whistles?

The ideal would be something like:
plt.imshow(2darray, barebones=True)