In this case it is entirely planned work: Anyone depending on docker.io chose to make their processes dependent on online endpoints with whose operators you have no business relationship. An unpaid third-party service going offline should be far from unexpected and if you rely on it you better be ready to cope without notice.
This is like complaining that you have to put out a fire because rather than fixing the sparking cables you have been relying on your neighbor to put them out before the become noticeable and he only gave you a short notice that he'd be going on vacation.
This is like complaining that you have to put out a fire because rather than fixing the sparking cables you have been relying on your neighbor to put them out before the become noticeable and he only gave you a short notice that he'd be going on vacation.