Monetary policy is about broad aggregates and the Eurosystem has a clear mandate to keep the eurozone’s general price level stable without taking into account the distributional effects of its decisions. Since micro data are all about the distribution of income and wealth, their usefulness for monetary policy is far from obvious. Indeed it may look anachronistic.
I remember the monetary policies pursued in many countries and in Greece until the 80s, where credit policies and selective credit controls were designed so as to channel funds to particular economic sectors (and even sub-sectors) while excluding other sectors from bank lending altogether. The implementation of these credit controls required a significant amount of micro data.