The Marvel Cinematic Universe is arguably the largest and most profitable mass on the entire planet (in cinematic terms, anyway). Since 2008, comic book fans have been treated to an average of two superhero flicks a year - all of which take place in a massive, shared world, inspired by the one that has existed since forever in comic book form. The appeal of this, of course, stems from the notion that Thor can pop into the frames of a Captain America movie and say "Hi." Or Tony Stark can reference something that happened in The Incredible Hulk. If there's one thing that can be said for sure about the Marvel Cinematic Universe, it's that it's expanding... and at an increasingly rapid rate. For most die hard fans who spend the days between each new MCU release simply gushing over what the next movie in the franchise might have in store, such expansion probably couldn't come fast enough. And yet beneath the surface of this billion dollar cinematic universe there is trouble brewing; with every added installment or chapter or sequel that Marvel Studios churn out, we push the MCU ever closer to its doom. Which is to say: at the rate it's going now, the MCU is not something that can last whilst sticking to its current formula. Constructed like a kind of cinematic Jenga tower, balancing the MCU has become a kind of game; one foul move and the whole thing could come crashing down. As it stands, Marvel seem to be well aware of the fact that they're treading on relatively thin ice; playing it safe seems to be their best and only answer. Join us, however, as we highlight 10 major reasons as to why - ultimately - our beloved Marvel Cinematic Universe is doomed to fail...