People seem to dislike the movie because of the final or because of the way the story is writen and shown.
I honestly loved the movie!! Sam did an amazing job, his acting was perfect, the way he speaks claiming that he is not crazy (when he actually is) is just spectacular. Also the story is told that way because we are looking at what the main character is living, we only see his perspective that's why it's so disorganized. And about the final, come on, not every final can be a happy ending like in disney movies, it makes you try to guess what is gonna happen next and i loved it, it makes you create theories on how it will end and makes you change your theories as the movie keeps going on.
Overall a great movie that is being hated by the wrong people.
I give it 8.9/10