OP has every right to be concerned and people dismissing those concerns shouldn't.
Security and privacy are similar to vaccination. It only takes a few to not take part and the entire herd is at risk.
Additionally, given the overall data accumulation that takes place online, this breach could be a problem.
Here's a hypothetical scenario: a person applies for a job requiring security clearance. During a background check, this person is found to be listed in a hacked database of 'illegal drug-buyers' and doesn't get security clearance. This could also be an issue getting loans, getting travel visas, and who knows what else.