Thing is that the idea has merit if it has been proven in double blind scenarios with controls.
This is not the case here.
We might not know everything about biological processes in agriculture and all the variables that come into play, however that doesn't mean that any idea that isn't part of "mainstream" agriculture has merit on its own.
We live in an age of mass production, I wonder what company would try to block farmers from producing more.
Also, no company can stop independent farmers from starting a biodynamic farm and produce more than their competitors thus being able to have even better margins.
So I think we can safely classify those kinds of worries in the "conspiracy theory" until proven otherwise.
Oh, I think you're being specious if you really have an interest in this subject but can't name a single company that would try to block farmers producing more using techniques from which the company can't derive profit... But hey, if you want to use the old 'conspiracy theory' saw to end the discussion, fine with me.
This is not the case here.
We might not know everything about biological processes in agriculture and all the variables that come into play, however that doesn't mean that any idea that isn't part of "mainstream" agriculture has merit on its own.