The point of backing currency with gold is to overcome low trust, or a potential future breakdown in trust. A claim to infrastructure that can simply be nationalized during a dispute / a military coup / etc, is not really serving the same purpose that a gold standard serves.
Plus, now you've somehow got to manage price controls on ports and infrastructure...
I've tried this point before but it always fails because the argument is, if I may contrive a straw man, that the government can simply machine gun everyone at the exits, take all the gold reserves, and cancel the notes. Therefore any government enforced asset is basically as good as gold in this regard because the government can and has (circa great depression) simply cancelled the trustless or bearer properties of gold.
Although you're right that this is historically a large element of gold exists it won't be accepted as reasoning, and it's not worth bothering on places like HN.
I think the hope that international bearers would have is that thet can get their gold out when the future is looking risky, but before a breakdown in trust comes to that level. Once the revolution actually happens, Fort Knox is in enemy hands.
> A claim to infrastructure that can simply be nationalized
If your currency is in such high demand that people still accept it, even knowing this, that's a feature not a bug. You hopefully never have to use but it remains as a nuclear option.
Plus, now you've somehow got to manage price controls on ports and infrastructure...