I don't see by what right people should be allowed to order living people how to dispose of their stuff after they're beyond caring.  I think people should be allowed to make generous gifts while they're still alive, without gift tax. (Though I think the recipients of those gifts should have to pay income tax on it; I don't understand why we'd want to tax income people get by working, but not income people get by being born.  Being born is about the most tax-inelastic thing you can think of.)  But once people are dead, then I can make a pretty compelling case that in a modern economy where extended families are not a major economic unit, there's little justice case for inheritance.