The question is not what anybody deserves. The question is who is to take on the God-like role of deciding what everybody else deserves. You can talk about ‘social justice’ all you want. But what death taxes boil down to is letting politicians take money from widows and orphans to pay for goodies that they will hand out to others, in order to buy votes to get re-elected. That is not social justice or any other kind of justice.
It is hard to understand politics if you are hung up on reality.
The fatal attraction of government is that it allows busybodies to impose decisions on others without paying any price themselves. That enables them to act as if there were no price, even when there are ruinous prices — paid by others.
Socialism in general has a record of failure so blatant that only an intellectual could ignore or evade it. Even countries that were once more prosperous than their neighbors have found themselves much poorer than their neighbors after just one generation of socialistic policies.
One of the common failings among honorable people is a failure to appreciate how thoroughly dishonorable some other people can be, and how dangerous it is to trust them.