Do proper research on your character's occupation.
If someone wanted to make a movie about a teenager who writes YA lit, they could easily look at the bestsellers list to see who teenagers must love reading about. Odds are they might choose an author like Stephanie Meyer (Not here to say hate about Twilight).
The main character in the movie is a writer who wants to be just like Stephanie Meyer.
While there are many people who are like that, I know many other YA authors who would shake their head and think that is stereotypical because it is.
That is the expectation of someone who reads YA lit.
A lot of writers would be upset over this movie, and the same can be said about other occupations and how we portray them.
I also hate the idea that all writers/ booklovers love the classics. I understand their importance, but personally, I hate most classic novels (probably because of how they are taught). Shakespeare sends me into fits of rage, yet I still consider myself a writer.
Not every person in a set group likes what is expected.
Not every artist likes Picasso.
Not every musician likes the Beatles.
Not every chef likes Paula Deen (I know the media with her right now, but I couldn't think of another big name chef that everyone would recognize)
One way to remedy this is by creating an idol like John Green did in The Fault in Our Stars.
Another remedy is too really research into what these groups like. Read blogs, youtube comments, forums, whatever.
Make characters more than what people THINK they like.