Isn't Anthropic currently doing "security through obscurity" for Mythos?

What's the worst that could happen if they were to allow unrestricted access to Mythos/Fable? A bunch of things vulnerabilities get exposed? And? A bunch of companies already had months of Mythos beforehand, and they probably fixed some issues it may have found on their codebase.

But ultimately why not allow people to use it to find vulnerabilities and then fix them? If mythos is so good and the average Joe can just hack NASA in 2 prompts, wouldn't you rather he did, and then fix the vulnerability? What good does it do any of us to just shush everyone instead?