If most estates consist of earned wealth instead of inherited capital, the suggestion I had would remove some of the argument for redistributing that earned wealth because it currently is not distinguished from what you think is a small amount of inherited wealth. This idea also addresses the issue that an estate tax reduces a person's incentive to save money.

The best counter-argument I can see is Tom's argument that property rights count more than anything else. It's just a matter of intuition whether one agrees with Tom that someone who's been handed money on a silver platter should have the same right to control its distribution as someone who did something to earn that money. I don't.

As for the cave "question", the original post discussed investments as earned wealth, as well as the concept of adjusting for inflation.