Those are very good comments. Again, it's the tolerance issue.
To give another analogy, I'm growing a Genuity Roundup Ready canola. Let's say I have a grower beside me who's using some new form of whatever, and that species ends up being a plant on my side of the fence that current herbicides can't control. I can name you a few that are minor crops. Should we also tell him that the dill or the new camomile cannot be grown in my rural municipality because he can contaminate me as much as he will be? It all goes back to tolerance, and zero is not an option.