You've fallen into the trap of an overly simplistic and narrow view.

When projects and people move away from DockerHub, it hurts Docker-the-company because it further decreases their already tenuous and evaporating relevance.

Reducing a fraction of storage and bandwidth costs isn't important compared to retaining mindshare and the perception of relevance.

Edit: @nextlevelwizard The explanation you requested has been provided. Now it seems you're disagreeing with a common, widely accepted phenomenon. I was hoping for a more collaborative interaction.