WhiteTower: because EACH GAME counts, towards statistics and final ratings.

No. Non-rated, non-tournament games don't count toward ratings or standings. And often, tournament games don't really matter for standings either - if for instance in a 6 player section, one player already has 5 out of 5, and you have 2 out of 4, it doesn't matter whether you end up with 2, 2.5 or 3 points - you're not making it to the next round anyway. Furthermore, in a N-wins match, draws don't count at all.

Finally, there's a tactical element. Suppose you're in a 6 player section. Your current score is 4 out of 4, your opponent has 4 out of 4 as well. There's one other section, and it's already know there's a single winner there. Suppose you, your opponent, and the winner of the other section are all equal in stength, so you estimate a 50% chance of winning any game between any two of you. If you play for a win, you have a 25% chance of winning the tournament - 50% chance of beating the current opponent, and 50% chance of beating the other winner. But if you go for a draw, your chance of winning the tournament increases to 50%! (25% of being a solo winner, 25% of joined winner). I guess offering a draw is the closest you can get to making a cube decision on BK. ;-)