Why are people making a big fuss over this movie? Sakura is the one that never loves Naruto and he deserve to be happy too. If Hinata is the woman that make Naruto happy then he can date her or marry her. If Sakura want Naruto to be her man, she has so many opportunities, but she refused to accept him and chase after Sasuke all this year. I love NS, but the outcome is too obvious.
(I'll edit this post later in case I mess up something; my phone is a bit wonky sometimes)
First of all, Sakura does love Naruto, whether it be romantic or not, and her feelings have not been made clear, because of Sasuke and the path he had taken. She was so focused on saving him that she cast all other feelings aside because she wanted team 7 to be complete again. Yes, she has feelings for Sasuke, but she also has conflicted feelings for Naruto, and until she finally realizes who she truely loves, that will be the end or beginning of NS. I agree with you that you say Naruto can date/marry whoever makes him happy, but throught the manga, since the Beginning of the story Naruto has had feelings for one girl and that girl is SAKURA. It has been shown that the girl who makes him happy is Sakura. She has laughed with him, suffered with him, and shared many moments with him. They have an unseperable bond and for fans to think Naruto would be a kitten or be selfish for being true to himself and not giving up on the girl he loves , is just ridiculous. I ship Narusaku because its the girl Naruto loves. This Story is called Naruto, not Hinata. So that's why it's important that he gets the girl he wants. The girl he loves and cherishes. The girl he has loved so selflessly. Wait till the manga ends so you guys can finally realize the 'romantic' aspect of the story that Kishimoto has been trying to write since the beginning. I might be wrong about this, heck I even have a feeling he might leave pairings open ended in these last chapters, but I'm sure if he does give tiny hints it will be Narusaku. So don't lose faith yet when the manga hasn't even ended.
I will support whoever Naruto chooses in the end, even if it is Hinata or Sakura. But you can't say that the romance aspect for Naruhina throught the story has been well developed, because there was never a Naru>Hina, it was always Hina>Naru.