This kinda reminds me of the conversation I had with my brother in law regarding the likes of SingAir, Emirates, and Qatar and just how much better they are when compared to US carriers that charge more on the same route despite providing an inferior product comparatively. He started on about how those air carriers are government subsidised, it's not fair, and I shouldn't be flying with them because of that. I told him I didn't care about the underlying business model, I want new aircraft, well trained staff, good quality food as well as service. Every one of those government subsidised carriers over deliver on every one of those metrics when compared to their US equivalents.
Sure, some people will take a stand because they feel the need to do so. But in general I don't believe most people care how their goods and services are subsidised, only that they believe they've received a better deal when compared to similar offerings from other providers.
For the person you’re replying to, it seems clear that the most important thing about the word “cost” is how much they personally pay — third parties are irrelevant.
“Sound”. “Cost”. The meanings of words are not as precisely identical as our subjective feelings tell us.
The US subsidises gasoline quite aggressively when compared to other countries around the world. You can see this in fuel costs; routinely US gasoline used to be cheaper by the gallon than Australian gasoline was by the litre. I've never once heard an American complain that their fuel is too cheap despite the fact that their taxes and government are directly responsible for said low cost.
So sure, people living in the US are paying those costs "as a whole", but you don't pay any additional cost when you order a package.
It's like how driving on public roads is free, in the common sense of the word, even though of course the costs are still "paid" somehow, by somebody.