For consumers it doesn't matter either, because they can always buy more bitcoins once they've spent some.
I have to call BS on this one, sorry.
If I purchased BTC @ $166 this morning to make a transaction 5 seconds ago @ $146.....that transaction would cost 12% (12% more bitcoin, which is 12% more USD as the store of value has changed) plus the spread, which is usually 0.5% - 1% and must be taken into account in merchant pricing through BitPay. And don't forget BitPay's 1% fee....minimum 13.5% in fees.
No, foreign exchange risk (currency risk) is actually a very serious issue. Hedging for this type of risk was impetus for the futures/forex industry.
And I would hesitate to call a panel that contains Nobel Laureates 'full retard'.