Think of it this way:
Imagine if I bought $1,000 worth of Microsoft stock years ago and it is now worth $1 million. Under the existing tax code, I would pay a capital gains tax based on a $999,000 gain if I sold it now.
Now imagine if the parents of the guy next door to me bought $1,000 worth of Microsoft stock years ago, then passed it on to him when it was worth $950,000. Under the "step-up" provision of the tax code, if he sold it today he would only pays a capital gains tax on the $50,000 difference between the $1 million current value and the $950,000 stepped-up cost basis.
This is patently ludicrous no matter how you look at it.
I’m not sure I understand your point. Why is it that you think the government has first rights on wealth accumulation that is passed to the next generation? It’s private property, they can do with it as they please.