For the first question, one answer is the high price of organics. For your second question, there are many options. One promising option is targeted pest and we

For the first question, one answer is the high price of organics. For your second question, there are many options. One promising option is targeted pest and weed control using cameras and image recognition and maybe even lasers. A system like that was actually mentioned on HN a couple of weeks ago. Another is using biochemistry to make pesticides that degrade and disappear before the food gets to market. Another is to bury seeds individually in the soil without plowing the soil, thus protecting the seeds from pests and giving them advantage over weeds whose seeds have to start on top of the soil. So there are many ideas out there.