Apart from the obvious (content not worthy of vote) it could also be due to timing: arriving late on popular posts (like this one); posting at times when the majority of HN is not active here (I'm posting from Europe). But I didn't think that effect would be huge...
Anyway, point is that 200 karma is a lot in my experience. Either I'm doing this HN thing quite wrong, DanG is doing it superbly, or "soon" is quite a stretch. Perhaps all three simultaneously?