I think he’s right, that the device has become a stock-in-trade of contemporary Hollywood; but I also think that its prevalence represents progress, of a sort, over classic-era Hollywood; the prevalence of long-range backstory is, in effect, democracy at work. Backstory is the rejection of the notion that a character’s inner life can be determined in any significant way from the way she looks or presents herself, from the outer marks of identity. It is essentially a distinctive way of overcoming the assumptions that people have the habit of making on the basis of race, ethnicity, gender, class, or social status. It’s a way of making movies that is consistent with the desire for inclusiveness, with the recognition that people cannot, in fact, be typecast fairly. The prevalence of backstory in Hollywood movies is one way that Hollywood has kept pace with, and reflected, changes in American society.