It is if you want to feed more people, More people may not be a good thing, but it often just is an inescapable reality and if you want to keep them from death by starvation you need higher yield.
And I'm not sure rejecting monoculture on a patch of land is high yield. Not if you want to harvest and distribute it all and do it before it spoils and the "patch" is large enough. Then you need machines, huge machines, and those demand monoculture.
Or you could go with human labor but then you'd need a whole other patch of land, harvested with machines, to feed the laborers harvesting the first patch.
Corn is a good example of high calorie/poor nutrition. But most other crops are not that bad.
Methods of harvesting and distribution depend greatly on how far one wishes to distribute the crop from the source. Which is entirely another prong in the argument for green ag. I don't necessarily agree with the local food movement on all accounts, but the question of feeding the world ultimately comes down to how much total food is necessary to feed a population, not how many diverse crops can feed a population. I know that sounds like an argument for monoculture, but hear me out.
High yield is important if you want to feed people outside your locale. It becomes less an issue of feeding the masses and more a vehicle for trade. Through modern techniques and distribution, oranges from Florida can be sold in North Dakota. However, I wonder if it's necessary that North Dakotan's need many cheap oranges. There are many examples. What is the actual value of Columbian asparagus in the fall vs. the residual costs of producing and distributing that asparagus? Et cetera.
The labor issue you bring up is an important one, however, and it is a trade-off that many proponents of green agriculture too easily overlook.
Clearly there's no vital need for cheap asparagus. That's another problem. As the Irish say: God gave us the potato blight, the British gave us the famine.
That is to say, whith great income disparity, even when millions of people can't get enough calories, we can be throwing away moldy oranges.
Shortages of food will only make it more expensive for us, but people around the world will starve.
And a lot of people are not eating specialty foods from far off, they are barely getting enough calories from high yield starchy local crops like rice, corn, wheat etc. I am not sure how you could provide a population center like say Kinshasa with enough calories, never mind trace nutrients, without machines. Manually harvesting wheat or corn is not a way to feed the world.
It is if you want to feed more people, More people may not be a good thing, but it often just is an inescapable reality and if you want to keep them from death by starvation you need higher yield.
And I'm not sure rejecting monoculture on a patch of land is high yield. Not if you want to harvest and distribute it all and do it before it spoils and the "patch" is large enough. Then you need machines, huge machines, and those demand monoculture.
Or you could go with human labor but then you'd need a whole other patch of land, harvested with machines, to feed the laborers harvesting the first patch.
Corn is a good example of high calorie/poor nutrition. But most other crops are not that bad.