White hat hackers do not require companies to pay them in exchange for not revealing a bug---the reveal of a bug only happens if a company doesn't fix that bug. Companies can be jerks and refuse to pay anything. That doesn't give you the right to blackmail them---you and other security researchers can just refuse to help them in the future.
A refusal to fix the vulnerability is what happened in the original blogpost, so it was fair game for release since the company doesn't care.
Hackers that don't care about ethics or legality won't bother blackmailing companies with vulnerabilities. They'll sell or use the vulnerability to steal more important data, and blackmail companies for millions of dollars in crypto.