[seanwitte]

I think the scoring is done this way to remove ambiguity. There is no need for interpretation. Say theres a big mound of bins. Which ones are in the stack? Scoring is simplified because they just count all of the scorable bins and measure the max height with that big pole. The score is just (bins - height) * height. Otherwise it would be impossible to judge and scores these matches without issues.

Addendum:

The dimensions of a bin are nominally 24.25" x 17.25" x 15.75".
One Stack Height Unit is 15.25". So, yeah, you're right. You cannot have a 6 SHU stack with 3 bins. BUT, with 4 bins you can stretch is out to a max height of 6 SHU. 4 Bins on their side would be about 96". Thats over 6 SHU, and allows a little overlap. Leave one on the floor you have:

1 carefully arranged stack of 4 bins, height = 6 SHU
1 bin on the floor
----------------------------
5 Scorable bins
Max Height = 6 SHU
Score = (5 - 6) * 6 = -6

The more probable scenario is the worst case of 0. Two bins, one its side would be (2-2)*2 = 0. The basic negative score would be 2 bins, one on its side on top of the other. Bins = 2, height = 3, score = (2-3)*3 = -3. If you take all of your bins and stack them up you get zero. If the top is flipped you go negative. If you can get a negative score you should get some sort of award...