A simple one is the comparison with 'passes completed'.
We have players who complete a lot of passes... sideways; the packing rate for these passes is 0 or 1. On the other hand, a player that doesn't just recycle the ball but passes through the opposition, for example McEachran or Sawyers, may score 3 to 5, and those passes are more likely to give the receiver - or the next receiver - a true scoring opportunity. A player who sits and moves the ball from side-to-side may complete 20 or 30 passes over the course of a game but score 15, whereas a player who makes fewer 'killer' passes, say only 4 'completed', may score 16 and his team are more likely to score from them. Obviously, your example of a 'keeper's punt is an exception!