As to your first argument, I don't think it's quite the same. This is like saying that when I buy a song I can freely resell it. Farmers aren't buying the crops and using it for personal use and giving it to friends for personal use. They are buying it and selling it on the open market.

If I personally went and bought Monsanto seed and used it for my own plants the I ate/gave away and gave it to friends who all used it for personal use, Monsanto would be hard pressed to stop me/they probably wouldn't bother.