In case anyone wonders who would buy these and why, the government has made it mandatory for banks to buy these themselves if they have deposits or loan. So this is effectively a tax on banks.
It can also be a deflation hedge. Let's assume your bond has a -1% yield and we hit -5% inflation. At maturity you have more effective capital.
If we hit -5% inflation you will have counter party risk for the US government to take into account. Not that I think it'll destroy the US govt, but it would make them declare your treasury bond invalid (and many others) rather than cutting spending even more.
I think the parent was answering the understandable question of why you would buy this instead of keeping it in cash.