Does it deserve a higher rating or not?

I looked this up on imdb and was surprised it didn't have a higher rating, but then I watched it again. I still love this movie but I do have some theories of why people don't like it. I think people don't like sad endings, and they seemed to push this movie as a comedy movie and then it turned out to be too sad for people. I also think they made the characters a little too unlikable - Jordana wasn't a very nice person in the beginning and it was kinda painful to see Oliver throw away his morals and start bullying to try to go out with this girl that was just being mean to him. Then Oliver started doing all these selfish things that made no sense, like when he planned on killing her dog, and he thought that was a reasonable thing to do and would make Jordana the same as before. That's what bothers me, he was so self centered that he didn't want to make her happy, he basically wanted her to get over her mom's sickness so that things wouldn't be tense between them. His first reaction when she told him her mom had cancer was "boohoo, now I can't tell her my parents might be splitting up". Then he broke into Graham's house and started peeing on things. Basically I think a lot of things in the movie are kind of exaggerated, like the characters have no empathy and I think we needed more reason to believe that they're actually a cute couple instead of a couple who just bullies each other.