That they don’t buy stuff is only half the story. The other half is they export a lot of primary produce - to the US, primarily frozen fish. The US imports a lot of food so they are interested in Falklands fish. US exports are much higher up the value chain, and Falklands having such a small population has rather limited demand for those high value exports-hence the inevitable trade imbalance.
Which isn’t saying US tariffs on Falklands is good policy-I think it is stupid.
Compare a country like Australia-like Falklands, Australia exports a lot of stuff the US wants to buy. Unlike Falklands, Australia has a decent sized relatively well-off population, who buy a lot of stuff from the US-as a result, the US actually has a trade surplus with Australia. Now, of course, Australia is on a completely different scale from the Falklands: but my point is, if Falklands had a ratio of primary production to population closer to Australia’s, the US would quite possibly have a trade surplus with it too, albeit obviously a smaller one-Australia has around 7800 as many people as Falklands, but only 750 times the primary exports - meaning on a per capita basis, Falklands has around 10 times the primary exports of Australia.
How is this not what I'm saying?
Go you.
https://www.bbc.com/news/articles/c5ygx81gpg6o