I think it's perfectly fair for them to say "we're not doing this any more". The sketchy part is deleting the public registry at docker.io/bitnami rather than just no longer updating it. Why can't docker.io/bitnami become the 'legacy' registry, receive no future updates, so at least folks who don't hear this news won't have pulls suddenly fail?

edit: like if I have a package on NPM and I want to stop offering it, I think it's shitty to just delete it. That breaks builds.