Replacing the income tax with an incremental property/savings tax probably would go a long way towards motivating people with wealth to use it or lose it.
That idea is dead on arrival in today's heavily lobbied climate, I'm afraid.
It's not just DOA due to lobbying - a great many people just don't agree that rich people should be forced to use or lose their wealth. Why should the govt. have the power to impoverish someone with a lot of money just because they're not generating more with it? That seems to me to be a fairly substantial abuse of their rights.
Who said anything about impoverishing anyone? What does "impoverish" mean, exactly, to you?
In France, the wealth tax is 0% under €800k, increasing to a maximum of 1.8% (once the person gets to ~€17 million). How could this lead to impoverishment when even relatively conservative asset management averages returns of >5%? Even in this case the party's wealth is still increasing (especially since the proposal is to offset the wealth tax by eliminating all capital gains taxes, which are already extremely difficult to calculate).
And it's hardly an abuse: property taxes (a kind of wealth tax) are already levied, and while many complain, few claim it is government overreach. Government policy that favors a small and already powerful minority would seem to be a much greater abuse.
The bigger question is: why do most governments tax people for creating value, instead of taxing people for failing to?
That idea is dead on arrival in today's heavily lobbied climate, I'm afraid.