From Longman Dictionary of Contemporary Englishbe a sad/tragic/devastating etc commentary on somethingbe a sad/tragic/devastating etc commentary on somethingSHOW/BE A SIGN OFto be a sign of how bad a particular situation is The incident was a sad commentary on British football. → commentary
Examples from the Corpus
be a sad/tragic/devastating etc commentary on something• The experience of some Sunday morning services in competition with golf is a sad commentary on the bending of principle to person. 