The board has 155,983 members of whom 6,826 are active. The point being that posters you see are probably not representative of the wider database. Figure 5% have bad security practices (conservative estimate, I would say) and 5% of those can be breached by a lazy hacker. 155983*.05*.05 = 390 vics. Score an average of $2000 from each and that’s $780,000 gross. If the hacker can skim 20% of that (for much of the hacking might be done by subcontractors or clients), that’s $156,000. So the incentives are there, especially in countries that turn a blind eye towards such conduct.
After first, second and third cuts on the data, the hacker’s clients could attempt reputational attacks, but only if the humor gods are willing.
To put all this in perspective though, Cupid Media once had 42 million passwords stolen.