I remember that quote from somewhere as well, but can't recall. There was a 'where are they now' article from 2005 called "Life After Xanadu" where Michael Beck spoke fondly of being Sonny. Also this little bit added to the multiple writers/no script detail:
"(I)t was difficult from an acting point of view, and I was a fairly young actor then. I would get revisions that had nothing to do with the story that I thought I was filming. And I would go, "Well, what am I supposed to be doing now?""
Link to story here.
Seriously, my love for this soundtrack is what still keeps this film nestled in a deep, dark, dirty place in the basement of my heart, only to be let out in a fantastic rainbow of roller fury when I am alone.
But if you think this was a fat rail of coked-up crazy, you should crush up the bathroom-floor-crystal-meth glory of another glittery musical debacle from 1980 called The Apple, directed by none other than B-Movie Maestro Menahem Golan of Canon Films!