You must not know any farmers or ranchers. John Deere gets more love than Ford, Chevy, and Dodge combined. I haven't ever met someone who has sat in a tractor without a positive opinion of this company.
Agriculture is a very technical industry, so most of these people are quite well-educated, but that education doesn't usually include software. As soon as someone in this field wraps their head around DRM and its consequences, they are likely to fight it hard, but getting to that point takes a little more explanation than it does for you or me.
In the grand scheme of things, at least in the short term, advertising "no DRM" isn't likely to make a dent in John Deere's market share.