I definitely agree that there is truth to Max Planck's assertion. And indeed, the Copenhagen interpretation was untenable as soon as it was put forth. However, Everett's initial theory was also very unsatisfying. It only became (somewhat) attractive with the much later development of decoherence theory, which first made plausible the claim that no-collapse QM evolution could explain our experiences. (For most physicists who examine it seriously, the claim is still very questionable).

Hence, the gradual increase in acceptance of the MW interpretation is a product both of the old guard dying off and the development of better theoretical support for MW.