I mean that you never want people to commit to keep money just sitting in nubits. It is costly to back nubits and the space should be reserved for users that are actively doing txns and generating txn fee revenue. Parking incentivizes people to do the exact opposite of what shareholders would like them to.
The reason this seems counterintuitive is because it is atypical. Normally a business investment may take years to generate a return, so the business knows it will have money 5 years from now, but is much less certain of its revenue next year. The business is willing to pay a premium to borrow for five years without having to worry about the creditor calling in the money.
Nubits is the opposite case. The system’s ability to repay USD tomorrow is relatively certain, but extremely unpredictable one year down the road. A comparable example is a business that wants an option to call in a bond before it matures. Say that your investment prospects have declined relative to prior expectations, but you promised to borrow for term of five years paying interest each year. You would like to be able to repay the bond early rather than just sit on cash and pay interest. You can do this if the bond has a call option allowing for early repayment.
Negative interest rates operate like a call option as well. You can say, hey nubits depositor I’m not sure if I will still be able to repay you next year, so I’d prefer to pay you back now. The nubits depositor could refuse. However, if we have negative interest rates we can say, either I pay you back $1 now or $0.90 next year, your choice. Essentially you can compel people to take leverage out of the system and prevent unsustainable accumulation of debt.