Sounds like you don't have anything to do with farming either.
Your comment suggests you have no good answer to the points I made about why children may or may not follow their parents into the family business, be that farming or framing, so you try and point out I have nothing to do with farming to distract from the real question:
Why children don't follow their parents into farming?
If you look at hay farming, in particular, the number of acres into hay has consistently been dropping since the end of WWII. Why? Probably because hay is used to feed horses, and farmers dropped horses for tractors. The only horses left are predominantly for pleasure. And we all know that horses are expensive and each year fewer people own fewer horses.
Combine that with the move of cattle to feed lots starting when, probably back in the 50's? and that accounts for another loss of hay users.
Then add into the fact that economies of scale have started playing into just about every industry in the world, and you're going to have more small operations (of any type, not just farming) be swallowed up by larger operations. That's just the way the world works now.
That's why farmers either take off-the-farm jobs, expand, or sell out. Look at the Amish. They have an 80 acre farm. Then they have 5 kids. That leaves 16 acres per kid. Can't do it. What happens? The Amish either move to other areas to buy up farms, or take jobs in factories like they do here. There are literally, tens of thousands of Amish people working in RV factories in northern Indiana. Why aren't they farming?
We have several good friends that are full-time farmers. Every one of them has jobs off of the farm as well. Mostly for the health insurance, and a steady, dependable income stream they can count on that's not dependent on mother nature and wild swings in commodity prices. Very few of their children have continued to farm after college. I can only think of two of the kids that got AG related degrees and continue to farm. Those two got out of dairy decades ago. One is all grain. The other bought into his wife's family horse farm, grain and hay. A 3rd one didn't go to college, but continues to run his family's dairy farm. 24/7/365. No wife. No kids. No off the farm activities. It's a hermit's life for him. My wife has a cousin that's the same way. 24/7/365 loner at her small dairy farm.
I do have a good understanding of a guy sitting by a fire looking off into space telling me what he really thinks about his past life while his eyes water up, wondering if he made the right decisions for his family by working so much. His kids are very grateful for the life he gave them, but that life is not on the farm.
And while technically, I've been a farmer since 1989, I don't consider myself a farmer. I have a tree farm with a USDA farm number and participate in farming activities. I actively maintain my forest and am a good steward of the land. The crop is due for harvest in about 30 more years.