2. Adapt The Basic Notions, Not The Themes Or Story
What The Studios Think: What makes something successful is not a great story or interesting message, but the characters, so no matter what youre dealing with, cut out everything from the source aside from the key set of characters. This way you get the limited iconography from your idea, but dont have to put loads of time into adapting a story very much of its time into the modern day.
Pro Tip: Fans rarely identify with the original themes, so throw out whatever was there before and replace it with something modern; something overtly environmentalist and anti-commercialism has been done so often, but dont let that stop you.
Why It Doesn't Work: Updating things is something you have to do if the film is going to be marketable, but doing it solely from that perspective isn't advisable. Theres no one thing that makes something initially successful, meaning that removing any key element is going to upset some of the fanbase. The theme is essential to the tone of the work and a new one cant be shoehorned in without completely altering the plot, which in a good source is entirely based of the characters. Everything is interlinked; you cant make the Cat In The Hat a pop culture quoter without ruining everything else.