Probably a little more like Larry Niven, but your point is well taken.
Although...I don't see it being able to be stretched any more than double per the description. Are we just extrapolating here, or are we just applying that sentence multiple times? I guess with a generous reading we could do that.A wall of stone is 1 inch thick per four caster levels and composed of up to one 5-foot square per level. You can double the wall’s area by halving its thickness. The wall cannot be conjured so that it occupies the same space as a creature or another object.