I'm thinking they just don't want the Law gear completely displaced by AlexN gear. Otherwise AlexN actually would be a great place (seeing it's the main "story progression" at level cap) to just award everyone an AlexN token per boss, and you can buy whatever parts with the designated number of the same AlexN token. Then put in special furniture materials, pets and mounts as random drops.

But if they do that, then Law gear will be completely displaced. So AlexN end up getting the RNG treatment.