My guess is that it takes very little time for someone who is not an optimist to give up farming. When things work well, the farmer does quite well. When they don't go well, the losses mount quickly.
Weather of all types, including rainfall, varies so greatly that nobody would plant anything if they couldn't tolerate the loss of at least some of the crop.
I was talking to an elderly man who farmed in west Texas when he was a young man. He recalled one year in which he had to plant his crops FIVE TIMES because flash floods or scorching heat or an untimely wind storm destroyed all his work. If he had been unwilling to re-plant the fifth time he would have had no crop at all.
The linked article explains that the trees that receive too little water are weakened and can become infested with insects and disease that can then spread easily to the rest of the orchard. Evidently they find it more economical to lose some of the trees to preserve the others.
The bottom line is that it is simply not as easy as it might appear to be a successful farmer.
Thanks for informing me of how tough it is to be a farmer. I wouldn’t have known otherwise. Oh, wait, yes I was raised on a farm with peach, pear, plums, persimmon, and pecan trees, peanuts and cattle that were all sold at market. We had chickens and a garden for home use. I still have a garden and pecan for home use and had to replant the garden last spring three and four times which you can verify on the FR weekly garden thread.