No, you're not missing anything, and I don't see how it could be fixed either. Actually, it works far better for younger people - they would get to save and not have their savings taxed. Older people with IRAs, savings, etc. would get royally shafted, because of double taxation. In other words, all the people who traditionally vote Republican would suffer MORE. Actually, that is a bit of a deja vu kicker, because as I recall the 1986 "tax reform" had the same effect. Imagine that.
No, that's wrong.
Older people with IRAs, savings, etc. are ALREADY getting shafted with double taxation. The current system taxes income and spending. The nrst only taxes spending.
Older people will be no worse off - indeed they will be exactly as they expected... BUT there will be no tax on any income they may earn, nor will there be a gift tax, nor will there be an estate tax.
Further, seniors currently pay the hidden spending tax on EVERYTHING they buy. The nrst has a zero rate on necessities. The nrst doesn't tax used items (cars, homes, etc).
So you're wrong to assert that the nrst would make seniors worse off.