When they first came up with the equipping to hands idea, it was all about dual casting, two spells, and not letting you do the Oblivion thing with sword, shield, and spell at the same time. Two weapons wasn't the priority, though obviously they had to put that in with this system. So, yeah, maybe a bit tacked on, maybe they put balance before realism to a degree, but I would take what we have any day over a 'dual wielding skill' that you get in so many games. Couple of perks, job done, everything else is down to skill with the individual weapons.