Answer: the American industrial food market decided not to invest in it. Literally everything that Americans eat today is a byproduct of the marketing of industrial food producers. If they don't want you to eat it, you won't see it. If they do want you to eat it, it'll be inescapable, visually appealing, and flavor-and-nutrition-bankrupt.
correct answer. boggles my mind how much nutrient lobbying goes on in the world....from demonising certain nutrients, to pumping others up. I grew up eating everything, trying everything, in a multicultural area...its quite odd for me not to have tasted something.
It's not like that in a lot of places, and it's easy to forget that!
Blows my mind when people say "oh wow i've never tried a [insert fresh food ingredient here]. You'd think people get curious about all the cool options you have to cook with...nope...a small percentage do.