Did you know that each penny can be used more than once in its lifetime, so the cost of minting is amortized across so many usages that it's almost certainly not worth trimming? This author didn't.
But each owner, including the government, gets to spend it once (unless they reacquire it by trading something of value for it). If I give away a Porsche, it costs me one Porsche. If you then sell it or give it to somebody else, and they give it to somebody else, and so on 1000 times, that doesn't help me. The cost to me is still one Porsche.
By your logic, if we could make a penny out of Adamantium that cost a trillion trillion dollars to make, it would be worth it, because the penny would last forever and be re-used an infinite number of times. But the cost of the penny to the government is not amortized across all the transactions it is used in UNLESS the government is a party to all those transactions (which it is not).
