Is there a canon explanation as to why Naruto still likes Sakura? What characteristic of Sakura makes Naruto like her? She was very useless in the original Naruto, and she is in love with Sasuke. Not to mention, she did not have anything traumatic in her childhood, unlike Hinata, who actually liked Naruto from the beginning. 

Also Naruto nearly unleashed the nine tails for Hinata, but still said Sakura was sort of his girlfriend. 

Did I miss something here? What did Sakura do to get Naruto to like her? I am only looking for canon answers.
I don't think there can be a canon answer to this because it is not something shown/talked about in either the manga or anime. However, when you were young what did your crushes do to get you to have a crush  on them? I know in my case, almost nothing. They just had to be attractive. My guess that is true for Naruto as well.