I think that is pretty poor reasoning.Small cages are not good for quail.
The one foot square area per bird is also to small.
Quail need room and some of these houses are way to small they dont have much space.
I see no reason to have excessively oversized cages, as it's a waste of space-- in both height and floor space.
When one square foot of cage space is required per one chicken- surely two quail a tenth the size- will fit into the same space with comfort.
I suppose it hinges on your beliefs, and thoughts- but in such production for meat and personal consumption of a product geared for that goal (conturnix quail)-- we should be max'ing output by min'ing input.