The problem isn't to do with GM, it's to with the way profits are derived from GM.
The modern farmer is first and last a business man.
He specializes. He raises grains, fruits or vegetables for sale in the retail or wholesale markers he understands or he evolves into a seed company or a nursery. Never both, because the labor and capital requirements are so very different and so very demanding.
When he buys seed from Monsanto, he is looking at the return on his investment, as any business man must. He is looking at how the product stands up against the competition. If it is sweet corn, he is looking at color and flavor. Yields. Resistance to insects, drought and disease.
The price of seed isn't what keeps a farmer awake nights. It is the environmental variables which can destroy any hope of a successful ---- profitable --- harvest.