Here you are completely and totally wrong. Bananas were a crucial element shaping US foreign policy in the early 20th century. There were multiple wars/conflicts started over bananas, and bananas constituted the primary cash crop of whole nations during that period.
The United Fruit Company (now Chiquita) harvested bananas across the Caribbean and Central/South America, and not only exerted large amounts of control over local governments south of the US, but also extended its control into the US itself.
For example, the US Secretary of State John Foster Dulles had represented United Fruit through his law firm prior to becoming Secretary of State. Oh and his brother Allen Dulles also happened to be director of the CIA at the time too. Oh yeah, and a board member of United Fruit. So here you have the director of the CIA and the Secretary of State, both deeply involved in a banana company, both pressuring the President to intervene in Central/South America.
And I'm only familiar with banana history during this period. Heck, maybe there were earlier banana conflicts.
Point of the story is that almost any resource can become something people will fight over. Under the right circumstances, it may be as mundane a resource as the banana.
EDIT:
I thought I'd add in my own personal feeling that as a lover of history, I too would like it if salt was included in the game. We're talking here about a resource that is absolutely instrumental to not only the growth of civilization on the whole, but also a resource that sparked countless conflicts. Were there wars fought over bananas? Sure. But they pale in comparison to the impact of salt.
So yeah, I'd love to see it in the game, but I do understand why it's left out. A lot of us here understand the importance of salt, but that fact is lost on many, many people. If I were in charge of the resources, I'd probably still leave salt in, but I think it's a hard choice from a game design standpoint, so I'd be fine with either having it in or leaving it out.
