This is an interesting article by Anita Silvey from School Library Journal that we here at Simply Read Books agrees with.
Her main argument in her article is that picture books shouldn't shy away from having longer texts!
Some of our recently published picture books definitely do have more of a story to them--such as The Boy in the Oak, The Melancholic Mermaid, Oliver's Tantrums to name a few. It's something we believe in.