I think the effect on small businesses and farms are vastly overblown. In 2013, 20 small businesses and farms were affected. The idea that estate tax affects family businesses is mostly a stalking horse for extremely wealthy who just want to save themselves money and whose descendants would still receive plenty of money even with an inheritance tax.
https://americansfortaxfairness.org/tax-fairness-briefing-bo...
The problem with many "wealth" taxes is that they end up missing the top 1% and hurting the people who are building a business.
Eg inheritance tax does a fantastic job of just screwing over family businesses that on paper are worth say $7mm+ because on paper the kids who inherit the business now owe taxes on maybe $2mm (I think the first $5mm is tax free w/ inheritance), but selling any of the business to pay the taxes would often destroy the business.
And I'm not talking about massive businesses like Walmart - I mean businesses like a large-ish family farm where just the land, equipment, animals, etc are all worth $7mm+ on paper, even if the farm doesn't produce massive profits.