The Simpsons has been such a major influence in modern culture that its effects be felt even in the modern English language. Quotes and characters from the show have become part of the social conscious, with some terms and ideas even being directly named for the show.
Once such a phrase refers to a show that is starting to lose its way in the writing, and it specifically mentions a certain Simpsons character. So, what does the term Flanderization mean, and what does it have to do with Ned Flanders?
WHAT IS FLANDERIZATION?
The term Flanderization is used in some internet circles to designate a fairly common writing flaw that occurs in long-running shows. As defined by AllTheTropes, Flanderization stands for "the act of taking a single (often minor) action or trait of a character within a work and exaggerating it more and more over time until it completely consumes the character." Typically, it happens the longer a series runs with the same cast of characters and the basic world -- and characters -- have to become to allow for new storylines.
When the show begins, the characters are oftentimes still somewhat broad, requiring the creators to flesh them out and explore more layers of them as the show progresses. But as the show continues and more (or most) ideas are utilized, it can become more difficult to not repeat jokes and storylines. While other minor characters receive more of a spotlight and a better chance to grow, other established characters can become pushed to the side and turned into more or less one-note shadows of their former selves.
This term applies to plenty of characters, especially of long-running shows. It especially happens to sitcoms, where the intended long-runs of the shows can paint characters into creative corners for the sake of simplicity and comfort. Infamous examples include Friends and The Office, which slowly added layers to their cast of likable characters only to turn them into walking punchlines when the creative juices of the show stopped flowing. But one character had such a transformation that he ended up with the term named after him: Ned Flanders.
THE PROBLEM WITH NED
Ned was introduced early in The Simpsons. He was initially set up as a perfect foil for Homer and not much else. Where Homer was brash, Flanders was polite. While Homer was thick-skulled, Flanders was always level-headed. That was the extent of the character early on until he was slowly fleshed out in the following seasons. He actually developed a personality, that of a relaxed and calm man who is content with the way his life has turned out -- a more genuine contrast to the more chaotic Homer that could still have his own foibles. Other aspects of his character were explored, such as his "friendship" with Homer, his strained connection with his parents, his teetotaller nature and most importantly his devout Christian faith.
In fact, his religious nature became one of his core aspects, defining many of his relationships and his general role in Springfield. It played into his personality and his actions, justifying his genial nature. This was only exasperated when his wife Maude died in the twelfth season, which introduced an interesting wrinkle to the character as a man in mourning who at times even struggled with the religion he's always turned to. But as time went on, his faith became the only consistent piece of his character, with the other complications and aspects fading away. As a result, other elements of his character (such as his constant kindness and internal grief) were pushed aside to make way for more jokes and stories about his religious nature.
It was eventually ratcheted up to the point where he was essentially as one-note as he was in the first season, only far more unpleasant as a result. Although there have been moments and stories about Flanders that have hinted at the character he once was (notably in his relationship with Edna Krappable and a genuine confrontation with Homer in "Bull-E"), he's largely remained a walking punchline. Other characters in The Simpsons have gone through similar transformations (with season 7's "The Simpsons 138th Episode Spectacular" even mocking Homer's even-then tendency to get dumber the longer the show went on), but no one suffered as much as Flanders.
He transformed from one of the few actually decent people in Springfield, someone that could bring out the worst and sometimes even best out of Homer, and became nothing more than a single concept played out across decades of television for cheap laughs. It's a sad fate for the character, but at least he's become a lesson for other shows -- don't let your characters fall prey to Flanderization.