Whatever happened to Uncle?: fine article from the Economist on the neglected children’s classic beloved of some Freaky Trigger writers. I think they’re basically right about the books and why they don’t sell – Uncle is a very ambiguous character, and the ambiguity provides a big part of the joke, and that did go over my head when I read the books as a kid.
What I took from Uncle was JP Martin’s prodigious imagination for nonsense – tunnels made of cake and fantastical swimming pools and so on, they all seemed wonderfully tempting. The subtleties of Uncle’s struggles with Badfort were kind of lost on me. Maybe there’s been a decline in kids’ appetite for nonsense stories – I can’t think offhand of any other great postwar nonsense tales, and the Uncle stories were actually written much earlier than their (posthumous) publication date.
The sad central truth of Uncle: the Bad is generally funnier than the Good.