The redistributors and egalitarians hate the institution of inheritance and want to use confiscatory taxation to spread the wealth. But inheritance is beneficial to everyone who are not heirs when it is mainly in the form of means of production and accumulation of capital, which increases production and supply, and lowers prices to consumers.
Withholding an inheritance to heirs by a parent might do more harm than good by preventing the productive heirs from benefiting consumers by accumulating capital and increasing productivity.