@Riphen: Some of the tournaments on this website operate exactly under that fashion. For example, the summer gunboat tournament is paying out points in a similar manner: "prize pool of 840

being split amongst the top three competitors: 100-240-500"
However, as other people have pointed out, many players don't play in tournaments for the points, but rather for fun, glory, and quality opponents. Hence, it seems that most tournaments just use a 5

bet and don't bother with redistributing points at the end. Pride, glory, and qualification/promotion for future tournaments and leagues are its own reward.
Building a reputation of playing well and improving one's Ghost Rank are much more meaningful indicators than points anyways.