Joe,
In virtually every case, heirs can keep their company if they wish and if they and their parents have planned properly. Even the Waltons essentially "control" WMT, all (or much of) the stock Papa Sam got over the years got put into a trust, guess who controls the trustees (or are the trustees)? And the children got lots of stock too. The Democrats wanted to make it easier for smaller businesses to pass their business down by increasing the allowable tax-free amount, as someone said earlier, but the Republicans, who are now so eager to quickly pass their tax cuts to help Americans even though they say that our economy is strong, didn't want to allow any tax cuts to pass Congress while Clinton/Gore were in office, so nothing got done.
The point to the inheritance tax was only partly to raise money, but even more it was to force some of the gargantuan fortunes that were being built up at the end of 19th century to be broken up or put into foundations that would, presumably, do some good. It was never intended to touch the vast majority of people. It actually worked pretty well. It isn't a tax on a dead person, dead people don't pay taxes or anything else, it is a tax on an estate. A long time ago, someone made up the story of Midas to describe the lunacy and the tragedy of people who believe that the point to life is to accumulate, accumulate, accumulate. The estate tax is a gentle way of reminding people that you can't take it with you, and you shouldn't even try. Republicans who feel that welfare is a "moral hazard" due to families getting $400-600/month per person max should reflect on the moral hazard of someone receiving millions of dollars in inheritance. The fact that there is no inheritance tax in most Central and South American countries has sometimes been given as a reason for their relatively stratified societies.