10 Reasons X-Men Should Never Join The MCU
1. X-Men's Story Works Much Better On Its Own
While the MCU has done a great job at incorporating the stories of various heroes into one shared universe, the story in X-Men is one that's best left in its own, because as a standalone series, its most prominent themes are so much more powerful.
X-Men, in the end, is about prejudice and fear of the unknown. It's about how two different social entities who are trying to figure out how they should coexist, with violent extremists on both sides of the fence, which only makes finding common ground that much more important. Just about all of the conflict in X-Men stems from humanity's fear or desire to control the mutants in some way or another. Therefore, parallels can be drawn between the stories this series tells and the prejudice, intolerance, and discrimination that exist in the real world.
By adding it to the MCU, a major portion of the weight that X-Men's social commentary carries would be gone. After all, for the most part, just about all of the super people in the MCU are hailed as heroes by the general public. So, this begs the question: why would they fear the mutants, especially the X-Men themselves who exist to protect them? Why would they cheer the Avengers, yet suddenly consider the X-Men a problem?
Yes, there are ways to make it work and the comics did it just fine, but there's absolutely no denying when it's just a matter of humans and mutants, the message is that much more weighty, compelling, and relatable to what goes on in our world.