I have nothing to base this on so take it for what it's worth.

I think it would be awkward and annoying to have that much extra material knocking around in front of and between your knees. Even with the light weight kilts I currently own I've not run into any modesty issues while sitting.

I could be wrong on this also, but I believe the top portion of the pleats are trimed off at an angle to eliminate the large amount of cloth that creates that 1/2" thckness and 14 layers of material.