Despite the fact that he was a popular success as a composer, Bernstein himself is reported to have been disillusioned that some of his more serious works were not rated more highly by critics, and that he himself had not been able to devote more time to composing because of his conducting and other activities. Professional criticism of Bernstein's music often involves discussing the degree to which he created something new as art versus simply skillfully borrowing and fusing together elements from others. In the late 1960s, Bernstein himself reflected that his eclecticism was in part due to his lack of lengthy periods devoted to composition, and that he was still seeking to enrich his own personal musical language in the manner of the great composers of the past, all of whom had borrowed elements from others. Perhaps the harshest criticism he received from some critics in his lifetime though was directed at works like his "Kaddish Symphony", his "MASS" and the opera "A Quiet Place", where they found the underlying message of the piece or the text as either mildly embarrassing, clichéd or offensive. Despite this, all these pieces have been performed, discussed and reconsidered since his death.