If you’re publishing a book do you go with something unknown that you think is good but you have to push it to get it selling, or do you back something ty at already has a celebrity springboard to launch it.
The point is that Walliams offers a very sweet deal to publishers. A famous name AND content that strongly appeals to kids. Best of both worlds.
There are plenty of examples of famous authors that get backing and bomb. He is not one of those.
Whether you rate his work or not, the sales figures and testimony of kids do speak for themselves.
Are there Unknown’s out there who are better? Sure. But why would a publisher ignore the gift wrapped package that Walliams presents to them? They exist to make money. They have limited time and resources to find pony’s to back.
As for Forrest, the target market would be significantly different for one thing. Also the boarding school genre has disappeared almost entirely (beyond Enid Blyton). No demand. That doesn’t mean that parent fans can’t seek them out, but they won’t be on the offer tables at Waterstones, no.