Humans can come up with arbitrarily weird damn explicit moral beliefs and metaethical theories based on false models, so trying to "rescue" them would be a bit of a nightmare and probably not even very nice to them if you acted toward them based on that, at least according to some pretheoretic intuitions regarding 'niceness' and 'help'\. Rescuing the explicitly mistaken model also seems liable to introduce large amounts of complexity and tension relative to rescuing the pretheoretic emotion instead\.
Are the them's in this sentence referring to different things? My guess is we're rescuing the theories and being nice to the people, but the differing them's are confusing.