Stupid, especially because he is a kid and young in his career. His lifetime earnings and ability to score a better paying job is worth way more than an extra couple thousand dollars selling this kind of exploit to criminals. It's why NDA's for security vulnerabilities are harmful because it doesn't allow a kind of social credit accumulation
Back in the day the US government would give you $20k-60k cash in a nice briefcase for this type of exploit. Just another thing big tech has ruined I suppose.