If they wanted to appeal to girls, then why not make Sakura the lead? She's the one female in the manga most regular girls can relate to, she's not the classic big breasted, 2D woman we see in Shounon Manga, Sakura was a classic example of a strog Shojo type heroine, she looks allot more like the typical Shojo heroine, her beauty is based on reality, she isn't made to ook perfect, she doesn't have big breasts, and perfect features, she is awkward, has issues with her forehead. Her personailty is the closest a girl could relate to, every girl has a first crush, one that doesn't pay them attention, they hope to find a love that makes them the centre of their world, would move a mountain for them to see them smile.
If Kishi wanted to make a Shojo movie he should have picked a Shojo heroine, someone the girls could relate to...maybe we should do a poll, we must have plenty of female fans of the series here right?
Which charactor can the relate to more, Hinata or Sakura?
You're absolutely right — Sakura is the normal girl. She's the strong one. She's the one with flaws. She's the one who's made mistakes and overcome them. It absolutely could have and should have been Sakura.
My theory is that the marketing team (made up of editors and artists and the promotions people within the umbrella company that owns Naruto) decided on the future of Naruto and chose the one girl who looked the most traditional Japanese. The most like the audience they were trying to attract.
And I don't think this was a Kishimoto-led decision. I think this whole beast was created by someone else, after RtN and as a way to extend the series after the end of the manga, and then it was pitched to Kishimoto.
Basically, Kishimoto might have had two choices: go with the marketing scheme that they've cooked up, support it, illustrate it and collect more money on it; or leave the manga with an open ending and watch the whole series be handed off to someone else, with him recieving nothing but royalty checks and having little artistic control.
Just a thought, but lots and lots creative projects have gone down that way before. Creators get fired, producers and directors come in and change everything. It happens. It's a business. I don't think Naruto, the brand, is any exception.
As for why Sakura over Hinata, I really think that it's because Hinata looks traditionally Japanese and her character is ridiculously passive and feminine. She's never offended anyone. Ever. She's is a pretty, flawless character. She exists to worship the hero. And in a nation that's right now having issues with women's roles and women's empowerment, Hinata might have been the safest bet at the box office, while Sakura would have ruffled some feathers.
Again, my armchair theories. But yes — it should have been Sakura. Something went wrong. And we just don't know what it was yet.