So many things are done with the end of making some profit, either directly monetary (bounties) or career.

People like these hope to get the recognition by the big companies to get the fat paychecks they dream to also pull in.

On the other hand, many others hack stuff and at most tell their closest friends.

Of course, it's availability bias: if this person wasn't disclosing it somehow, you wouldn't know. And even just a random article online is basically a disclosure minus the other benefits, so people contact the OEM while they are at it.