I once had to read a few of his kids books against my will. I thought they were horrible. Not in a fun The Twits kind of way, but in a way that I thought children should not be encouraged to think.
Like Gangster Granny begins with the lad not liking his granny because she's boring and old fashioned. ...You mean, she's an old lady? Who doesn't like their granny because she's an old lady?
So she starts doing her gangsta act to impress her grandson, because she's sad he doesn't like her. I guess I'm being too literal here, but it made me think of all the old grandparents who would read or watch this story with their grandkids, and worry their grandkids felt like this about them. Most people would like to be more "fun" and "cool" for their grandkids, but being elderly limits your energy and your physical capabilities. They can't just suddenly start being cool.
I know, I'm reading too much into it, but I thought it was bizarrely mean spirited.
Then there was one where a teacher was nicknamed Mrs Fuzziwuzzi or something "because of her frizzy hair" - she was black!! Wtf!!