I would guess costs or possibly time. They would have had to make another mold for it and they definitely wanted it ready for the biggest knife show of the year. It looks like they barely finished it in time as it is.
As I suspected, the knife was made in one mold and just as forecast by the Liquidmetal Blog:
Note the specification cites:
Overall length of the Hybrid Knife™ is 5.0 inches, and weighs approximately 2.7 oz / 76.5 grams. Current limitations per 100 gram ingot is a wastage of 20 percent for the sprues, grab handles, etc.
So, that doesn't leave much room for the third part if you are trying to make the knife as large as possible and still make both halves in one mold.