The case in favour rests on the idea that credit-financed asset price booms, when they reverse, are likely to be highly contractionary for the economy. This may well be over a horizon longer than the usual one to two-year forecasting horizon, so that conventional forecasts may not capture these dynamics.
But over that longer horizon, on this argument, the economy will probably be better off if the boom is smaller or stops earlier, rather than later. Policy which responds to the boom to an extent greater than required just by the short-term outlook may assist this.