What is the motive? Comparing the whole of reddit with HN will do no good. Obviously reddit has more users because of its diverse set of sub reddits. Or is there anything i am missing here?
We all know that Reddit is far more large than HN. To me, the chart serves to illustrate how far Digg has fallen, and that reddit's profile has risen far above Digg's greatest height. Meanwhile, HN is steadily gaining ground, albeit in a much more narrowly focused area of topics, as you note.
