True. But as the original post was about the possibility of using a shield and two-handed weapon, your point is more geared towards that person than to me.There's one very obvious mechanical difference. Using only magic armour leaves you with a free hand to do something with. Using a shield means that hands full.
I was merely pointing out that I don't think there's any need to force the player to use a feat or feature to be able do it, while having no opinion on whether doing it at all is or isn't a good idea.