Firstly his father had attacked because of both suspecting Farma's medicine and that Farma wasn't truly his son, especially when seeing his notes. And even then, he didn't persistently reject Farma's idea. Not to mention, you just said it yourself that supernatural influence played a part, which wouldn't always be a case in our society, as instead that would be a surefire way of making someone think that you're crazy and shouldn't be handling medicine in the first place.
Second, did anyone besides his father try to stop Farma when he went to administer the medicine to the Queen. Because if we go by your logic, the whole room would've swarmed the kid to get him away from the Queen regardless if she were as good as dead. After all, like the father said, no one wants the Queen to suffer further humiliation.
But they didn't. They allowed him without showing opposition, and allowed him to show his abilities and listened to his explanation.
So the point goes back to, there isn't any reasonably functional society in our world that would've allowed that, even if the gifted child had their parent's go-ahead. So the fact that you're still trying to apply logic like that, almost 60 chapters later is silly, especially when such logic never applied in the first place.