You are right that it is not 100% true, but it is mostly true.
The US uses corn syrup because the US government heavily subsidizes corn. Some Mexican producers in Mexico do use corn syrup, which is a cheap import from the US, but even here the majority use sugar.
This kind of thing happens in with other countries as well. In New Zealand you can get local coke which is sugar-sweetened or imported American coke with corn syrup. People didn't switch to corn syrup because it's better or even cheaper in and of itself, they switched because the US government goes to ridiculous lengths to make it cheap.
Maybe not "heavily". It was 2B out of a 50B corn crop. So, 4% classed as 'heavily subsidized'?
And a large portion of this is in the form of insurance against bad weather/crop loss. Otherwise, we'd have no farmers left in a couple of year (everybody has a crop loss once in a while).
They invested to get the market to 50b at the expensive of other products that could have been grown. The 2b figure just helps keep the edges from fraying.
If something else had been supported to get that generous crop, we'd be dissing it now. Like VHS vs Betamax, Corn won early and it won big. Not surprising it went like that; so many things do.
Anyway it'd cost trillions to retool for some other staple crop now.
It's less that corn is subsidized and more that the US has a system of price supports for sugar. The price of sugar in the US is significantly higher than in other countries, so food producers have an incentive to use alternatives.
The US uses corn syrup because the US government heavily subsidizes corn. Some Mexican producers in Mexico do use corn syrup, which is a cheap import from the US, but even here the majority use sugar.
This kind of thing happens in with other countries as well. In New Zealand you can get local coke which is sugar-sweetened or imported American coke with corn syrup. People didn't switch to corn syrup because it's better or even cheaper in and of itself, they switched because the US government goes to ridiculous lengths to make it cheap.