Well before 2000 the goal of gratifying intellectual curiosity was served with less convenient tools, and the limitations of a bare text medium arguably greatly enhanced the process. The history of success HN has with its elegant simplicity is another great argument for the existence of that effect.
Of course the presentation is a vanishingly minor factor compared to things like excellent moderators, well articulated policy, and an engaged, interested community.
Because its simplistic i guess. A nice site like this is a rarity in today's world.