Saying FG is worthless is based on nothing. Njaguar saying it has no monetary value is true, but anything you spend time on to get it has value. Just not monetary.
An easy indication of this is archeological value. A simple pot is worthless. A pot dating back to the 5th century however, a different case.

Anyhow, there currently isn't an extreme devaluation of the currency to buy FG. Thus this isn't relevant.

In the event of rampant hyper-inflation of the USD (should such an event come to pass), I will take pro-active measures to ensure that FG value does not become diluted as a result.

If such an event comes to pass, possible courses of action may include: reduced FG / $ valuation, no longer accepting it as a purchase value, etc.

In short, don't worry.