You do know this is a test run, right? And we are also only a week into the new system? I think it's good that this post has gotten popular, since I do think that matching elements on armor to elements on mods should allow that mod to be cheaper, rather than exclusive to those sets. But Bungie is testing the water with this, and personally I didn't bother much with armor until the change. Overall, keep in mind that this is a fresh build and that it hasn't been done in Destiny before. Chances are if the idea catches on, Bungie will change up how it works to make it a bit easier to implement.