What a stupid process. It bothers me that farmers rarely own the land too. We can't shake our tendency to let wealth turn us into tiny little kings that live off the rent. (not so tiny in the case of farms, but you get it).
If you raise crops or farm animals, you are a farmer.
The USDA is not trying to pull a fast one with the definition of a farmer.
We could have a discussion about farmers that have other jobs and so are part time farming and part time something else. That tends to correlate with less intensive farming like corn and soybeans.
Is a massive agribusiness conglomerate a farmer? Most farmland in the US is "owner operated". But really, that just means it's not rented out by a non-operator landlord, which is the distinction that USDA article makes.