Family homes rarely exceed $13M but farms and ranches can get up there. Seems like it should be easy to exclude agricultural land, but there's second-order consequences.
If farms and ranches are the best place to hide family wealth, then family wealth will pour into agricultural land. That inflates values and pushes out the actual ranchers and farmers. If farming is just a byproduct of your tax-avoidance strategy then you are unlikely to try too hard at it. We actually need farms, and nobody wants them to become tax-avoidance shells.
If farms and ranches are the best place to hide family wealth, then family wealth will pour into agricultural land. That inflates values and pushes out the actual ranchers and farmers. If farming is just a byproduct of your tax-avoidance strategy then you are unlikely to try too hard at it. We actually need farms, and nobody wants them to become tax-avoidance shells.