Which is probably an intended part of the analogy.

On the other hand in these orgs you have people crying "iceberg!" all the time.

But they are so big and strong that there would be no danger from an iceber... oh

So many examples of this. Blockbuster vs NetFlix seems like one.

Blockbuster v Netflix is odd though, in that Blockbuster actually did pivot to the DVD by mail subscriptions really well.

Well at least operationally it was a good product, and imo better than Netflix's, but I have no idea if helped or hurt them financially.

But Blockbuster's established sources for content/disks should have been an advantage against the stories of Netflix having to go buy retail copies of movies in cases of uncooperative distributors.

It was just Phase 2 and moving to streaming where they fell so far behind. (Plus Redbox's uprising didn't help, which is a separate failure to pivot.)

That wasn't necessarily inability to steer. Blockbuster had an opportunity to own Netflix at one point and said no. Just like Docker was given a chance to steward Kubernetes and decided to compete against it instead.