Exactly. In fact, Gene Roddenberry said as much in the original TOS Writers' Guide:
It's amazing how many professional and fan writers ignore this very basic advice that's as old as Star Trek itself. It's one reason I think the TOS Writer's Guide should be required reading for anyone writing any kind of Star Trek story.
Explain to me how some trek writer translated a real-world makes-sense situation into The Immunity Syndrome
You fail to see the point. Forget about the specifics of giant amobea, or ghosts. It's about how real world humans would react when they are confronted with things like that. Are the character's motivations to do something believable? Etc...
And again, just because there are examples how sometimes they didn't follow the advice, doesn't mean it's wrong advice.
The objection comes when you couch this particular bit of advice in terms of "This is what Gene would do" or "This is what Gene said to do" when in fact Gene can-x-ed his own advice on a regular basis, starting with the original pilot, and he didn't really give a damn if his writers ignored his advice either. His basic criteria for approving a story - whether he ever admitted it or not - was "Is the girl in it hot?" and "Will I get all the money and credit for producing it?" Every other comment of his on the subject is Hollywood Boilerplate.
I didn't say the advice was wrong. What's horseshit is that Gene Roddenberry or any canon writers killed themselves trying to follow it.