New Brevoort Formspring

I don’t know that “need is quite the right word.

First off, the definition of "retcon” has changed over the years, from what it originally described (“retroactive continuity”, inserting new stories into the past, such as the Invaders) into a catch-all for any story that changes anything or reveals anything about pretty much anything. At this point, it’s so broad that the revelation that Darth Vader was (spoiler) Luke’s father would be considered a retcon, in that it came in the second film. So some of what you’re talking about is simply storytelling, coming up with and revealing new things about the characters and the world they inhabit.

But in its purest form, the appeal of the retcon is really due to its sales potential. Fans seem to respond to nothing so strongly as stories that reveal that “everything you know is wrong”, to coin a catchphrase. It’s been that way since at least the early 1980s, when Alan Moore in particular applied the principle to just about every established character that he wrote for.

In a practical sense, though, we’re talking about characters and stories that have been going on for fifty to seventy years depending on how you choose to count it. And in that time, countless creators have contributed their ideas and executions to the tapestry of the history. And not all of those contributions and contributors are equally good, and what worked and was relevant in 1966 may no longer work and no longer be relevant in 2014. (For one thing, if Iron Man’s origin took place in Vietnam pre-War, as it did originally, he’d be really, really old today.) There’s virtually a necessity in making adjustments as we move along, simply because we’re carrying around a larger amount of aggregate backstory created and commissioned by a wider array of people than anyone else in the history of fiction.