Defederating everyone defeats the purpose of the free speech aspect of the fedi we're all bragging about. Defederate bad actors (people who just want to see the fedi burn and go out of their way to exploit bugs to do so) and people who post blatantly illegal shit, but please leave other instances out of the mix, everyone deserves a chance to express their opinions. Even if they're offensive as hell.
Should definitely have clarified this post is aimed toward instance admins, users are free to do what they want with their timeline. I believe admins should not be defederating everybody they see, users should have the say in their timelines.