If the moral conventions of ethical life have decayed and been blightened by the free market, with only fragments remaining, then we are going to find it difficult to 'breathe' in the old language. The old moral language of modernity (utilitarianism and Kantianism) is saturated with the conditions by which western culture was able to produce the great art and thought, and then to produce death camps with the efficiency of a factory.
Tis something that is difficult to hold onto in these conservative times.
One can understand why Adorno said that to write lyric poetry after Auschwitz was itself barbaric. I presume Adorno would say the same about ethical philosophy. Ours indeed is a destitute time. We live in the void.
What we can say is that ethical philsophy could still be written, only not as we had known it. Philosophy would have to change in order to rebuild the tainted home of ethical life in which live and find our nourishment. What is required is a new language, a new philosophy; one that would be a way of turning us toward that which is absent in our everyday world; an ethical life that has some meaning and substance, and is able to offer us some guidance in how we should live.