Why is Krugman a hack? An excessive increase in savings causes a reduction in spending which causes the economy to slow which causes people to use their saving

Why is Krugman a hack? An excessive increase in savings causes a reduction in spending which causes the economy to slow which causes people to use their savings. Savings aren't really an investment, or at least not a very good one. The utility of savings is to smooth out changes in expenditures in relation to income. Some savings are good as a cushion to protect against temporary declines in income, in the same way body fat was a good way for our ancestors to maintain their energy expenditures when their food intake was insufficient (in the short term). Savings aren't an investment because the return they're expected to yield is not greater than inflation. This is why someone says they "invested" in something that should ordinarily be considered an expense, you know they're making bad financial decisions.