Not quite. Those people WILL grow more food, because they will adopt 50's style herbicide and insecticide use. Exactly what occurred in India and Pakistan in the 60's.
Most of the big chemicals are cheap, and really raise yields. Not too too healthy (debatable)especially as they are used in the 3rd world, but what the heck? As long as we don't have to eat perfectly healthy GM foods, that's ok with the Luddites. Probably not so ok for the local wildlife and so on.
I'm pretty sure the idiots in question didn't think this competely through.
Actually chemicals and sophisticated farming equipment are expensive for farmers. Especially when you need to apply that stuff every season on the field. And what if pests dont get your crops, what if drought does? The bottom line is the environmental Luddites don't care if food can be made cheaper and better tasting. They want us all off the planet.