Personally I feel they should actually go "You can have as many of a card in your deck as are provided in one copy of the product). It would mean that "incomplete" core sets would actually be complete, and it would allow the creation of cards that are ok on their own, but would just be utterly bent if you had three... as you couldn't have 3.
Of course that is not the way they are going to go...
Why don't you think so?
"Truth has power. And if we all gravitate toward similar ideas, maybe we do so because those ideas are true…written deep within us. And when we hear the truth, even if we don't understand it, we feel that truth resonate within us…vibrating with our unconscious wisdom. Perhaps the truth is not learned by us, but rather, the truth is re-called…re-membered…re-cognized…as that which is already inside us." Peter Solomon, The Lost Symbol