“In Foucault’s 1971 televised debate with Noam Chomsky, Foucault argued against the possibility of any fixed human nature, as posited by Chomsky’s concept of innate human faculties. Chomsky argued that concepts of justice were rooted in human reason, whereas Foucault rejected the universal basis for a concept of justice. Following the debate, Chomsky was stricken with Foucault’s total rejection of the possibility of a universal morality, stating “He struck my as completely amoral, I’d never met anyone who was so totally amoral” … “I mean, I liked him personally, it’s just that I couldn’t make sense of him. It’s as if he was from a different species, or something”” (from the Wikipedia page on Foucault)
Morality is an evolved sense; different societies have evolved different moral structures. In this sense Chomsky and Foucault are each half-right.
The point, though, is less about what morality is, as about how humans think of morality in other humans; Foucalt is particularly distant from anything most people (especially most Americans) would recognize as moral.