I think it's a simple matter of people's familiarity.
When you talk to new Canadians, they tend to like and want to attach to the traditions we have. There's a sense that new Canadians want to know who we are. They want to know what they're joining. They want to know who we are together and to integrate and attach. They want to feel proud, and they want to know why. If they see us constantly picking away at our own heritage, I think they'll find no fixed term of reference, and we start to look as if we don't know where we came from.
It's rather like poetry. We memorize poetry by repetition, but if the words keep changing, we'll never be able to learn them.