That's true. The general rule I go by is carry between 3-5 months worth of expenses (debt service + living expenses) in cash and the rest goes into various investments to make more money. The cash is my emergency fund and the investments are my savings.
If you leave 18 months worth of cash in a savings account, you're losing value to inflation.
Under normal circumstances I would agree with you. Locally, if it takes a software developer 3 months to find a job it means that they took a 2 to 2 and a half month vacation. On the other hand, almost all the software jobs locally are defense related and with all the pending budget uncertainty(combined with volatility in stock and bond markets) I am currently carrying in excess of 1 year expenses, for my definition of expenses.
If you leave 18 months worth of cash in a savings account, you're losing value to inflation.