Makes sense. Shipping containers would have to be tied down somehow, so if they had holed planks already installed on cargo ships they would save handling and time. The pointed jugs could also be tied together in freestanding masses of three or more that would be perfectly stable.
The pointed jars were used for wine transportation. Since the Aegean sea is extremely rough, they pointed the bases so that they could easily be staked in sand, which would help prevent the jars from breaking during transportation.