In general there's little value to doing full disclosure. It's a net loss for the reporter (no bounty payout), for the users (they could be negatively affected) and for the company (that has to deal with the fall out). However, in some cases it's necessary to act in that way in order to get things fixed. If a company is being obtuse, lying, or otherwise not fulfilling their obligations to their customer then there's really no choice.
Full disclosure is still good, because it will wipe bad service providers from the market and teach careless users a lesson. And the reporter's greatest asset is not some change for reward, but great achievements in his vita.
Companies have to die at some point, and some users unfortunately have to learn their responsibilities the hard way.