As a Nebraskan, I resonated with this - big time. My first question is _always_: "How does it make money?", and I've shied away from ideas that had no clear money-making potential. It is likely the predominant 'agricultural' culture.
Ironically, farming is kind of like a startup. You raise millions in capital to get started, and then you work for many years without making a cent in hopes that one year you'll finally hit it big.
With that said, I farm in Canada. Perhaps the subsidies you American farmers have access to changes the dynamics.
Others bank on the sale of all the assets when they retire. A farm that cost $25,000 30 years ago is now worth $1.6M. But when you are starting out, you have no idea what the future will hold. Just as many defaulted on their loans for those $25,000 farms and are no longer in the business.
Traditionally (this has certainly changed with corporate farms) farming has been strong family history and bootstrapping (likely via loans for land/equipment purchase) rather than investors.