Not how it works. If you go public before patenting you can no longer patent it. Just how it works. Think there is a 2 week window or 2 month window or something once the new thing is public and for sale to patent. After that, poof. They have no claim to it. It is public domain, not about who has claim, because no one does. Until you change it. Not about your agreement, how you feel about the plant, or opinion, its about patent law and the precedents that have been set.
Whether that is how it should be? Not what lawyers study. Just how it is.
Edit: its 12 months grace period. So those dudes from the 60s are like me, SOL. Not to mention any current strains are unpatenable since its illegal on the federal level. Until that goes away no ones patenting anything like this.