You have a weapon to attack with, why do you want to attack with something designed to block? ...
This is simply wrong for authentic shields - and an apparently. still widely missunderstood fact. Shields have basically always been designed for agressive use, as part of a weapon-set - you should lookup some material in the net, its very interresting. You could aswell implement arrowreflecting greatswords, since they where certainly tried to be used defensively like that in some cases - always there had to be a balance between defensive and agressive abilities obviously.
Its also easily comprehensible, that there would be no reason to
not use a shield as a weapon, and if you fight for your life , you would certainly try to exploit any given option you got...
Thus i would not mind if the trend would go that way, opposed to the paradigmatic, usual unrealistic 270°+ forcefield item implementation, that most games and movies showcase and imply. I think it would as well greatly benefit the gameplay, if shields would trade some defense for aggression in terms of active applications to use.