WARNING: CONTAINS MASSIVE SPOILERS.
For those of you who have seen Big Hero 6 (if you haven't, stop reading this article and see it as soon as you can!), you may have noticed something familiar about the last ten minutes.
In summary, near the end of the movie, Baymax and Hiro go through a portal to another dimension to save the villain's daughter. In the process, Baymax's suit is damaged, which means his wings are unable to function. The only way he can save Hiro is by using his rocket fist to send Hiro and the villain's daughter back out the portal. Reluctantly, Hiro turns off Baymax and is sent back through the portal, leaving Baymax to float for eternity in another dimension. Soon after going back through the portal though, Hiro finds the chip that powers Baymax clutched in the rocket fist. From this chip, he is able to rebuild Baymax and live happily ever after.
This kind of ending, according to tvtropes.org, is called a "Disney Death." It is a situation where a protagonist seems to be killed off only to be brought back to life or only assumed to be dead.
We all know how these scenes go. First, the hero falls into a pit or seems to be killed by the villain. Then the hero's friends hang their heads in sorrow and assume the worst. Finally, the hero makes a triumphant return to applause and embraces. Audiences love to see a story end happily after terrible things happen to the characters. Believe it or not, this trope has been around since the first ever Disney film, Snow White and the Seven Dwarfs.
Remember the scene where Snow White lays in an eternal sleep in a glass coffin? The funeral scene where the animals of the forest and the dwarfs are waterlogged in tears? Indeed, Snow White's fate seemed to be sealed, only to have Prince Charming deliver the kiss of life and wake her up.
There are several more examples of the Disney Death in other Disney movies:
Beauty and the Beast
and even Frozen
It even happens even more in non-Disney movies:
The Rugrats Movie
Pokemon: the First Movie
The Iron Giant
The Spongebob Squarepants Movie
How to Train your Dragon
and Cloudy with a Chance of Meatballs
However, despite all of these examples, I felt that the one in Big Hero 6 is not worth complaining about. In fact, I think it works more in it than most other examples and is actually worth praising. The reason why actually makes a lot of sense when you think about it.
Baymax is introduced as a healthcare companion. After the death of Hiro's brother, Tadashi, Baymax serves as Hiro's caretaker. Without Tadashi, Hiro was unmotivated and depressed. He showed no interest in being around anybody or doing anything worthwhile. However, along came Baymax to help him out in more ways than one. He is designed to support Hiro and help him overcome his personal struggles by any means necessary.
Even if Hiro doesn't want to be helped, Baymax knows what is best for him. It was Baymax who called Hiro's friends to help him catch Yokai, and it was Baymax who refused to let Hiro remove his healthcare chip again after almost killing Yokai. Baymax doesn't cater to Hiro's wants, but his needs, much like Tadashi did when he was alive. Remember when Tadashi took Hiro to his school instead of to another illegal robot fight? Hiro wanted to go to the bot fight, but Tadashi did what was best for him.
Speaking of Tadashi, when Hiro first tells Baymax that Tadashi is dead, Baymax responds with "Tadashi is here." This phrase is misinterpreted by Hiro as something everybody says when someone dies. However, since Tadashi is the one who built Baymax, Baymax is metaphorically Tadashi. It is extremely likely that Tadashi programed Baymax to take care of his brother in the event that he died, which is why he programed Baymax to say he was "here." Tadashi essentially lives through Baymax.
This theme of Baymax being Hiro's guiding light culminates in the "Disney Death" at the end. Baymax once again puts Hiro first on his priorities. Again, he is programmed to help his patient by ANY means necessary. Baymax knew that at that moment, the only way to save Hiro was by staying behind in the alternate dimension. Even when Hiro refused to deactivate Baymax, Baymax did not stop commanding the action until he did so. However, it is not just a simple sacrifice.
Baymax knew exactly what he was doing, which is why he clutched the healthcare chip in his fist. He knew that Hiro still needed him. Since Baymax represents Tadashi, his actions show that Tadashi programmed Baymax to stay with Hiro to keep his brotherly love alive. It also shows that Tadashi rightfully has faith that Hiro can rebuild Baymax with the chip alone. Though the fighting chip, the armor and the expensive robotics were lost in the alternate dimension, Tadashi's heart and soul were preserved by Baymax and simply transferred into a new physical entity.
This is why the Disney Death works here: because it really means something. It fits in with the larger themes of caretaking and brotherly love. If Baymax had dove into the portal to save Hiro only to fly back through it, it wouldn't have the same impact as the way it was done in the film.
At the root of things, yes, it is another Disney Death. However, it is a trope and not a cliché, so it can still work if done correctly. In other animated films, the Disney Death only serves the purpose of adding cheap drama to the ending and faking the audience out. Big Hero 6, in my opinion, did it exceptionally well. The truth is, familiar story elements are bound to happen with all of the stories told since the beginning of humanity's ability to tell them. However, like sour cream in a chocolate cake recipe, as long as the filmmakers can tie a trope into a worthwhile story, it can blend perfectly with the rest of the film and result in a magnificent whole.