The tax is levied on the estate before the remainder is distributed so its arguable on whom the tax is levied. If someone has worked hard and invested prudently, both for their benefit and for the benefit of their descendants, it is not fair that the government steals a portion of the estate.
But only when you spend the money. Inheritance tax is levied on all the money that you haven't spent, plus the current value of a property that you might have bought 30 or 40 years ago for only a small percentage of the current value. Inheritance tax is robbery.