Warning! Spoilers ahead for Young Sheldon season 6, episode 19. Despite having a lighthearted tone, Young Sheldon season 6 reveals the true villain of The Big Bang Theory franchise. CBS struck comedy gold when they took a chance with Bill Prady and Chuck Lorre's nerd-centric sitcom. While The Big Bang Theory wasn't an immediate hit for the network, with its original premise even needing significant changes before it got to air, the show eventually found its base. Four years since it ended after 12 seasons, it remains one of the most popular sitcoms thanks to its availability on streaming platforms, not to mention being always on broadcast re-runs.
In an effort to further capitalize on The Big Bang Theory's success, CBS greenlit its first spin-off, Young Sheldon. The prequel serves as Sheldon's origins story, tackling events from his childhood while he lives with his family in Texas. Admittedly, Young Sheldon's approach to continuity is very bad; it has contradicted the established canon far too many times at this point. That being said, the network maintains that the shows exist in the same reality. Taking this into consideration, Young Sheldon season 6 may have just revealed the true villain of the whole The Big Bang Theory franchise.
In Young Sheldon season 6, episode 19, "A New Weather Girl and Stay-At-Home-Coddler" Sheldon develops an odd feeling that he is falling behind in life. Despite his intellect, he hasn't done enough to beef up his post-grad portfolio. Instead of owning up to his lapses, he starts blaming Mary, accusing her of coddling him, which results in his complacency. Even George agrees with this observation, saying that he has long warned his wife about her kind of parenting. Looking beyond Sheldon's academic prospects, however, Mary is a big part of what he eventually becomes in The Big Bang Theory — a man-child who is selfish and self-aggrandizing.
As a sitcom, The Big Bang Theory didn't really have a true villain. Granted that there are annoying characters who tend to annoy the Pasadena gang such as Barry Kripke and even Wil Wheaton, the show didn't have any recurring antagonists. From a storytelling perspective, however, Sheldon used to be the one who wreaks havoc. His eccentricities and unreasonable behavior had given his friends grief throughout the show's run. It didn't help that he demeaned, inconvenienced, and mocked them endlessly. Sheldon wouldn't have developed some of his most problematic traits had it not been for Mary coddling him.
In recent years, Young Sheldon has started diversifying its storytelling. This means that instead of Sheldon always being the center of the show, all his family members are given their respective compelling narratives. Doing this allows CBS to have a more dynamic and interesting TV series, but it also highlights just how annoying Sheldon has become. Despite his occasional ability to self-reflect, his antics have seemingly only gotten worse in season 6. Mary is partly to blame for this because he continues to coddle him.
Missy actually touches upon this point in Young Sheldon's "A New Weather Girl and Stay-At-Home-Coddler." While Sheldon feels sorry for himself, his twin points out how he tends to wallow in self-pity and wait for everyone else to feel bad for him. During dinner later that day, Missy also mentions how Mary tends to coddle only Sheldon but tends to disregard her other kids.
Arguably, Sheldon was at his worst at the beginning of The Big Bang Theory. Despite his painfully slow improvement, it's clear that he made some significant progress over the course of the show. Truthfully, he couldn't have done it without the help of the Pasadena gang. Unlike Mary who coddles Sheldon in Young Sheldon, his friends actually held him accountable in The Big Bang Theory. Penny was the perfect example of striking a balance between being understanding and fair when dealing with the socially-inept genius. She approached him with patience and kindness, but wouldn't also let him get away with being rude or mean.
Young Sheldon season 6 airs Thursdays on CBS.