Large estates are mostly family businesses, farms, gas stations, retail stores, truck stops, dry cleaners, restaurants, homebuilders, and dealerships. The deceased's estate is pretty much the business. He may have a few thou in the checking account, a decent house and a nice car, but most of the estate is the business.
So, lets look at things from the standpoint of the business. It's been humming along, employing people, making a profit, getting by. It hasn't been growing 10% a year, its cash flow is on the tight side, but as long as the owner stays alive, it will continue being an asset to the community.
Then something bad happens and the owner dies. The business is willed to the heirs, and all of a sudden, it/they (business/heirs) is/are liable for humongous amounts of estate tax. The heirs don't have that sort of money. Neither does the business. In many cases the business is liquidated to pay the estate taxes, the employees are laid off, and the community looses a local business.
In short, the estate tax, death tax, is a killer of small businesses. Those of us who have operated small businesses know how difficult it can be to keep the doors open. That's tough. Even tougher is starting a business up from scratch. So the liquidated businesses don't grow back. When the estate tax forces them to liquidate, they stay liquidated, and the community looses the employment, the services, the taxes, and the civic support that local businesses provide.
In short, the estate tax anti small business. The really fat fat cats, like Bill Gates and Warren Buffet have foundations and pricey lawyers to keep their fortunes out of the clutches of the government. The estate tax doesn't hit the rich, it hits small business. Estate tax demands that small businesses cough up incredible amounts of money every generation and few small businesses have that sort of money.