With inflation, existing debt becomes easier to pay and income taxes and property taxes rise. With deflation, tax receipts fall and debt payments become even harder to pay.And that includes the public debt. Basically, it's a way to help pay down the public debt by, in part, sucking the value out of people's retirement savings.
Inflation sucks the value out of people's retirement savings? Not as badly as this does, because with inflation people collect interest on their savings. With 0% interest on savings, retirees are spending down the principal. For younger retirees, that spells disaster. And for those over 50 or so, low interest rates mean their savings aren't growing in preparation for retirement.
The stock market is rising, sure. But the elite who finagle those things will pull their money out when it's maximized and "games up". The other thing is to get to that money anyone invested in the stock market has to pay capital gains, so it isn't really as much as it seems.