The irony is their policy here seems carder-friendly. Instead of pursuing legal action against the person who owes them 12.5k (which the freelancer would presum

The irony is their policy here seems carder-friendly. Instead of pursuing legal action against the person who owes them 12.5k (which the freelancer would presumably support) they express no interest in legal action and simply don't pay the freelancer. If the freelancer got scammed by the carder, the carder wins. If a carder sets up a freelancer account to pay himself, that freelancer account is going to withdraw the funds ASAP, and Upwork informing that account they must do the next 230 hours of work on the platform for free isn't going to be an issue because they don't have any real reputation to lose or real work with pending payments so they can move on to the next dummy account. But yes, the ultimate solution is getting "Robin" to pay. Upwork which owns the client relationship and has the resources to pursue fraudsters should be leading on that though.