You're reading it today, when big noses don't immediately make you think of antisemitic stereotypes, /because that's not what antisemitism is today/. When the books were written, it was.
The thrust of your argument is, Roald Dahl "turned off" his antisemitic thoughts then wrote a book with all these antisemitic tropes in them?
>>lozeng+(OP)
He wrote a book about witches. I suggest you go and check out the noses on caricatures of witches if you can't bring any previously seen to mind.