Just got to thinking this (AGAIN) when I was doing some Bama Bug last night....
My guess is that the machines make them that way so that is how we all are a custom to the laminate process. For hand pouring, side by side would be easier and you would NEVER have cold cracks... Great for worms, maybe not as good for swims....

Hmmmm.... Guess I had better patent this process real quick before posting...


Pardon the quick, poor picture....
Jim