"If my father croaks and leaves me $1m it should count as an additional $1m of income to me that year. "

If it is $1m in property value, do you count that as still $1m of income? If so unless the child is in great financial situation with a lot of already liquid cash, they would be forced to sell part/all of the property to pay the taxes.

If a parent croaks and has a small business, mom and pop style. How would that be handled? If they had a small corner store making 100k/profit but has no assets vs a shop that sells very expensive equipment making 100k/yr in profit. But has hundreds of thousand in assets that would pass down.