Though this isn't quite on topic, Broken Deck brought up an interesting alternative to this. The effects of this would be pretty similar only a bit more extreme.
What if all the moxen and black lotus were errataed to say Global Artifact. Similar to Global Enchantments like Nether Void and The Abyss, you can't have more than one Global Artifact in play at anyone time. I think this could work well. By opting to play power cards, you risk having cards in your hand rendered useless by an opponent who opens with a mox.
But I digress, the above suggestion probably won't happen. So let's get back to discussing the original idea.
If you wish to discuss the validity of the critical mass of restricted cards arguements, please do so
here.The linked thread has a million and one arguements suggesting that type one is increasingly becoming super fast combo meta, is on the verge of reaching critical mass, and will inevitably collapse on itself forcing people to leave if something isn't done. Phantom Tape Wurm is the strongest advocate of this.