> The default grey background with white lines was just pulled from one of Tufts's books without a second of thought b/c these grey backgrounds are horrible waste of ink when printing

I don't follow. If it's a waste of ink, why were they in a book? And why is it bad to copy them to ggplot, which - well, I don't know whether print or screen or neither is considered its primary focus, but there's no denying that it's used a lot for screen graphics, and those don't need to worry about ink.