Many argue that this focus fits with the comparative advantage of monetary and fiscal policies. It is widely believed that monetary policy has no effect on long-term growth rates for real GDP, aside from the benefits arising from achieving and maintaining price stability. In particular, beginning from a position of price stability, more accommodative monetary policy cannot raise the economy's long-term rate of growth.
This means they will typically respond to signs of second-round effects which might emerge if, say, other prices or wages began to change in response to the initial oil price effect. But where there is a persistent trend for some particular price to rise quickly over a longish period because demand is strong, the case for ignoring that is weak.