The war against cash is coming
This is the best reason for alternative currencies
Negative interest rates are the pet project of incoming Federal Reserve Governor Marvin Goodfriend. He believes the FOMC needs to power to make people pay to deposit money in the bank.
It's a wildly unpopular idea and it's also one that's currently impossible to implement -- people can simply use cash.
The solution is a crypto-dollar. A digital currency sponsored by the government that could be taxed if it's hoarded rather than invested.
I can never see that idea getting support in a democracy but if it were ever implemented, it would be the greatest boon to gold and cryptocurrencies in a generation.
Bloomberg has more on what Goodfriend would like to do.