The idea of a decentralised marketplace for hackers and cybersecurity specialists to make protection systems for companies to purchase is promising. A big drawback is that it still doesn't address the skills crisis, even though it would theoretically change some black hats to grey/white hats it still doesn't provide the increase in volume of cybersecurity specialists that is needed. I'm going to write something about blockchain in education as it's very under-represented in IT courses.
There would also have to be a strict vetting process to make sure that these black hats turned white hats aren't using this marketplace as a way to get easier access to systems.
This is not to say that blockchain has no place in cybersecurity, there are plenty of viable applications for blockchain technology when it comes to security. I see blockchain technology playing a major role in the future of authentication process', record keeping and of course the major one which is payments.
Let me know what you think blockchain can do for cybersecurity, I'd love to hear your thoughts