It seems weird to say "And because (as we learned earlier) we read word by word, too much spacing between words breaks this rhythm" as a reason to avoid justified text, and then immediately after say that you can temper bad justification by telling it to auto-hyphenate words, so now "masters" is "mas-\nters" and "artisan" is "artis-\nan". That seems like a much bigger hit to quick readability than the poor justification they were initially complaining about. Their "better" example is easily worse than their "bad" example for readability, I would think, and to my eyes it's a bigger difference than between their "bad" and "good".

The spacing between words is better in the "better" version than the "bad" one, but if the point is that we read by words, then breaking up words across lines seems like a much graver sin than bad inter-word spacing.