With civilised margins you can run a column of text in a readable font and the lines turn out neither too long nor too short, and everyone camps happily. In the normal course of things the most practical size for a book is about octavo, digest-sized, or A5. Good choice of fonts depends what looks good and reads easily in the layout, but layout is constrained by format, and choosing a good format in the current technological circumstances is really tricky. Thus they wrested open a thorny can of worms.
