Why does Katniss seem so nice in the book but in the movie she talks to no-one and she seems like she hates everyone.

Honestly, I didnt see it that way. Katniss wasnt that talkative in the vitabu either. She might have just seemed like that because she was the narrator, so it seemed like she was always talking. I actually found her a little cold in the book, but she had reason to be after what she went through.
In the movie she specifically says that she is not good at making friends. She's not comfortable with other people, so I think that is why she can seem stand-offish.Plus, the only people we see her with before the reaping are Prim, Gale, and her mom. The only one of those that she seems to not like is her mom. After the reaping she has reason to be mad, nervous, quiet, etc.

she is the same in the movie and in the books. wewe are just being delusional.

I think that the movie is too short to onyesha all the aspects of her complex personality. She wants to look strong and brave. For her, every shown emotion is the sign of weakness. But, actually, she's just sixteen mwaka old girl who desperately wants to protect her family.

Because the vitabu are better. Hollywood isn't good at inaonyesha 3-deminsal characters, they underestimate their audience and think that people wouldn't root for a complex character.