I don't get your point at all. The celebrities are actors. They are playing people who are not themselves. That is the whole point of acting. If you want to criticise the acting performances, the casting choices or debate about the merits of films v books that is fine but to say a film cannot work because 'celebrities' are cast in roles that aren't anything like their real lives is just daft. Should they have cast a bunch of Edinburgh heroin addicts in Trainspotting?