Kelly Jensen rounds-up the plethora of reasons why adults read YA sourced from the near weekly blog posts and news stories on why.
You can them all (I suggest you do, they’re very funny)
1. Our culture encourages an unnatural and prolonged adolescence
2. YA books are escapist since you don’t have to look beneath the surface of them. They are easier to grasp.
3. Adults read YA because they aren’t able to read past a middle school or high school level because adults are getting dumber and dumber.
4. YA books are about hopefulness. Their problems aren’t really problems and they can be fixed. Also there’s always a happy ending, so it’s satisfying and fulfilling to adults. The characters are likable.
5. Fill in the blank with your own justification here. Some examples may include: YA is all about first experiences; YA is nostalgia for adults; YA is cheaper than adult books and therefore more appealing to the wallet; and so forth.
Or you can skip right to the end: because they want to.