Paul Cornell takes nearly 3000 words to explain why in Doctor Who “there’s no such thing as canon”.
It’s a good and eminently sensible read, and I agree 100%. Jonn Elledge, (a decent chap I haven’t spoken to in years), sums up my perspective on this. Many of us who enjoy Doctor Who pick up knowledge of the series through osmosis, and see it as something as a curse, a by-product of obsession rather than something to aspire to. Others see knowledge as a badge of honour and seek to classify what they don’t know or want to know about as wrong and “unofficial”.
And yet I think the rest of us can be a little too scornful of those who seek to define canon because they feel to get full enjoyment they have to know everything about the whole story there is to know., and so feel the need need to limit the scope of the story in order to limit the task of knowing it. I certainly have little tolerance for such people, but perhaps for a quiet life should hold my (virtual) tongue more.
I think canon is used more as a weapon to exclude things that people don’t like. You will for example get far fewer people who are fans of the books arguing that they are ‘canon’ than those who argue it’s silly to say they aren’t. But in the end most of us have moved on and let those interested in the silly term preach to their own choir.
Because at the end of the day, who in their right mind cares?