What is the weakness of existentialism?

Question

What is the weakness of existentialism?

Answer 1

It's bloody difficult to follow.

Seriously, though. Heidegger criticized Sartrean existentialism in 'Letters on Humanism'

"Existentialism says [that] existence precedes essence. In this statement he [Sartre] is taking existentia and essentia according to their metaphysical meaning, which from Plato's time on has said that essentia precedes existentia. Sartre reverses this statement. But the reversal of a metaphysical statement remains a metaphysical statement. With it he stays with metaphysics in oblivion of the truth of Being."

Roger Scruton also criticised Heidegger's concept of "inauthenticity" and Sartre's bad faith. He said "both deny any universal moral creed, yet speak of these concepts as if everyone is bound to abide by them. In chapter 18, he writes, "In what sense Sartre is able to 'recommend' the authenticity which consists in the purely self-made morality is unclear. He does recommend it, but, by his own argument, his recommendation can have no objective force."

Answer 2

Everything it represents.