Well until the industrial revolution, organics was the only option. Chemicals came out as being cheaper and more potent so most farmers flocked to it and got bigger yields as a result. Years later we found out that using chemicals leads to big environmental problems like leeching, and it would often get into the ground water, or nearby lakes and streams killing the local wildlife. I've heard of biologist yell about some fertilizers causing big toxic algae blooms or dead zones. And for farmers it turned out to be a double edge sword. They would get big yields for a few years until the fertilizer slowly killed all the organisms in the soil and caused so much salt build up that nothing would grow. On top of this you also had issues with pesticides causing cancer and hurting the ozone. Eventually people started looking for ways out and all of a sudden organics just kind of exploded again.
Science has also stepped in quite a bit and has help both the organic and chemical fertilizer industries. Many big scale farmers will do more soil testing and crop rotations to compensate for the problems of chemical fertilizers. Organics have benefited from better understanding of macro and micro nutrients. A few years ago no one was really selling bat shit, but look it's all the rage now.
Now it's almost like a challenge... who can grow yields bigger then the chemical guys, all the while doing it much ethically and with less harm to the environment. While the chemical guys are taking it a step farther by introducing GE crops -- these crops often are more frost and pest resistant, giving them huge advantages in yield and less pesticide usage. Although this is still unaffordable to the home grower.
Organic growers (especially the cannabis type) also claim their product tastes and smokes better. If you grow it right and blind fold me, I'm not going to be able to tell. I think it's mostly in people's heads but some people will swear on their mother's life that there's a difference and from a business perspective, if you got some people who will only buy organics, well, your going to offer organics.
So.. yes Chemicals are more potent. But Organics are easier and more ethical to use. And the differences are getting smaller and smaller each year.
