1. Continue operations of the family farm, assuming you can come up with the money to cover taxes.
2. Sell the farm to Big Farm, Inc., get a $5M check and forget about it, regardless of the consequences that means to your customers.
Inheritance, even with normal tax, is a cheap way of keeping money in the family and keeping rich people rich. It is not based on merit, capabilities or need and serves no purpose in a society based on improving the lives of the entire population. (Which you can argue is not what [country with low inheritance tax] is)
I would say that society is served well by the ability of widows to inherit and not be left destitute. Similarly for minor children.
If you're talking specifically about inheritance by adult children, I agree the arguments in favour are weaker.
If you have $300 to your name, you're not getting finance. The bank will just laugh you out the door.