Why is existential theatre so divisive?

with existential theatre, most people either love it or they hate it. the concept of existentialism is to question the meaning of life. are we really living? what is our purpose? do we just live to die? Samuel Beckett and Harold Pinter prodiced some amazing 'theatre of the absurd' as it has been refered to.. what are your opinions of this style of theatre? have you seen any performances or scripts that you thought was interesting?