Even if it's one in ten thousand, the system still needs to be resilient to being exploited to malicious actors. Many cases of mental issues are caused by genet

Even if it's one in ten thousand, the system still needs to be resilient to being exploited to malicious actors. Many cases of mental issues are caused by genetic factors and chance, not environment, to address your argument specifically. And of course there's plenty of incentive to ruin things for others: having a monopoly on something is the best way to profit, and destroying competition helps a lot.