There are actually two kinds of “theories” about anything.
—Falsifiable and non-falsifiable
—Falsifiable theories means that the advocates of that view could change their mind if certain new information was verified to their satisfaction.
—Non-falsifiable theories means than no new facts or discovery could ever disprove the theory.
Imho the first type of theory—no matter how unpleasant or how difficult to believe—is not “nuts”.
The second type of theory is nuts.
From children maybe. From grown adults, no.