But the thing people complain most isn't because they want to delete everything but because they need docker rm, xargs and complex bash foo to delete the containers and images they don't need.

For example I want to delete all old and all untagged versions of an image. I want to delete all stopped containers that use a specific image, or that were created more than two weeks ago. I want to delete all images starting with test.

Nuke everything? Not so much and to be honest this would be the easiest even with xargs and docker rm.