I think that the thing is, I pretty much exclusively get into canons after they're over. I only very rarely become invested in active canons! Which means I already know what to expect from character arc issues going in and can be braced for them. And then the few times I have followed active canons....if a character I love is ruined for me by canon, then it's probably part of a bigger overarching issue with canon and the whole of canon is ruined for me. (eg when I had my horrible breakup with Doctor Who many years ago)