The Bee Gees blamed their declining popularity in part on their involvement with the whole project, coupled with their mutual struggles with drug addiction. The latter was exacerbated by the environment of making the film and its soundtrack, with Maurice Gibb expressing shock at seeing crew members carrying around bags full of cocaine. Robin Gibb in particular spent much of this period having to dose himself with barbiturates to even be able to sleep. Some of the most vicious criticism of the soundtrack was leveled at them, and the musicians felt a particularly painful sting at being labeled as mere "Beatles imitators" since that sort of pejorative tag had been with them since they began their pop rock work in the 1960s. (Although the Bee Gees would continue to be popular into 1979, that year's backlash against disco, a genre in which the band had made their biggest impact, marred their careers permanently.)