From the August 3, 2012 print edition of Entertainment Week on the 20th anniversary of Goosebump, R.L. Stine concludes the interview with this quote (I can't find a link online):

I try not to put any messages in my books. Really, I Just want kids to say, "Gee, I can turn to a book for just entertainment.!"  The rule for children's books has always been that characters had to learn or grow in every book. I tried to break that rule.  The kids [in my books] never learn. The just run away.

I totally agree.  We want kids to love reading, but we also seem obsessed with learning something every second of every day.  All that learning must be exhausting.  It's nice to give them a break and just have let them have fun every now and then.  Imagine, kids not reading about empowerment and self-esteem and drugs for half an hour.  We don't want them to see sex, violence or drug use in movies and video games, but if that's not  in a book, the book isn't worth reading.