Under the supply and demand theory, Tobacco then makes food crops cost more by reducing the amount of farmland available. Unless it creates land for farming that otherwise would not be productive.
You are both right and wrong. A profitable tobacco crop takes up far less space than food crops of any type, and yes it can often be grown where others crops would not be productive.
That IMHO is exactly the problem with something like Gubmint subsidies for Ethanol production. It bastardizes the free market...
And the resulting symptoms are higher corn and beef prices.