I think the orientation question can add a lot of confusion. When you apply a force to a kayak which way is the stress oriented? I suppose if you suspend a kayak from its ends and is in the middle a substantial amount of the stress is lengthwise, but the stresses end up getting distributed. There is a force trying to collapse the deck and hull together, this is counteracted by the sides of the kayak which are put in compression, so part of the skin is subjected to transverse stresses. If you make the boat too weak either longitudinally or transversely, the boat will break.

But the supported-by-the-end senario is not likely, it is just one worst case. the other worst case, with the boat balanced on a sharp rock is more likely. This puts something like a point force on the bottom. The stresses can propogate in any direction around 360 degrees. If the bottom is significantly stiffer in one direction than the other, that direction will load of with the stress first and start distributing the stress along that axis of stiffness. Since that is the direction the composite is also stronger it is able to handle stresses that might break other orientations. Since the forces are not well oriented one way or the other, the stress will follow the stiffest orientation.

There is also the problem that wood strips are much stronger along their length than across. This means they don't need as much reinforcement along their length as across their width for balanced strength.

It is a complicated and confusing syste which is hard to analyze.