How to Ruin My Teenage Life

I'm so confused. How do people like this novel? I'm 18 years old, so I am well over the recommended age for reading this novel. At first, I thought that was why I hated it. But there's more to it. I have been reading for most of my life. While I appreciate the deeper themes of diversity in the novel, I believe they are not executed well AT ALL. The writing is absolutely atrocious. I do not believe any 8th grader is as stupid as this authors implies they are. There is no mystery in the novel with why the main character is acting a certain way. Almost too much is explained rather flatly to the reader.

The main character herself is certainly very spoiled and extremely immature. It's very painful to read and she is not likable at all. Just...definitely not a good book.
Could not finish it. Then, I looked at the first pages of the other two books in the trilogy thinking the writing may mature with the age of the main character. Boy, was I wrong. If anything, it got worse. Do not recommend for any literate teen girl.