I find those arguments irrelevant. as for DESIGN!!!
dim shield is fine, its not until people break the game by imposing limits on gameplay that its a problem.
oh, so you take one example deck, that can beat another deck, but if you change the second deck suddenly it wins... no kidding mate.
I think you are biased as master of aether, and you think this shield is just super great. Dim Shield is fine as is. Other cards will come into play, just new cards were introduced to Aether, giving a current, slight advantage. Remember, originally, Dim shield was one of the only things Aether had going for it. Time passed by, it got better cards. Now, perhaps, it has an edge. Thats normal, Aether is in flux. In time, other elements will get new cards and Aether will be out of swing. Dim Shield is fine in the long run, other elements will get new cards, there will be new counters. Dim Shield doesnt need a nerf.