I believe "fair taxation" demands that "all income sources" be included in the income tax code. I would tax inheritance as unearned income and treated it similarly to long-term capital gains. Rather than using "step up," I would adjust the basis for inflation to calculate "real growth" as opposed to inflated "nominal" value. I would compromise on a modest "base deduction" for inheritance.
Current drafts of various tax "reform" bills entail elimination or, at minimum, sharp limitation of estate tax provisions. In recent years, this form of taxation has been routinely caricatured as the 'death tax' by opponents. But a proper understanding of this tax is that it is an aristocracy or plutocracy tax intended to prevent multi-generational concentrations of wealth and power.
The Founders understood this to be fundamental to the preservation of a democratic republic.
Noah Webster, in 1787, made this perfectly clear:
"An equality of property, with a necessity of alienation, constantly operating to destroy combinations of powerful families, is the very soul of a republic--While this continues, the people will inevitably possess both power and freedom; when this is lost, power departs, liberty expires, and a commonwealth will inevitably assume some other form."