It also comes down to to both the presentation and the subject matter, I think. Something about the Surgeon's Photo, for example, feels kind of spooky even knowing how it was made. The high contrast of the image doesn't provide much visual information and so imparts a feeling of mystery. And, while implausible, the idea of an elusive survivor of an otherwise long-extinct species being captured on film isn't as unbelievable as a plant that grows pasta is (although it makes sense that people at the time fell for it given how they weren't familiar with spaghetti).
It's still worth watching the clip, however:
The whole thing kind of reminds me of this:
These old legends seem to hit the sweet spot for me a bit more due to how intertwined myths were with actual history back then and the almost limitless possibilities of what could be thought to exist in faraway lands back then, whether it's vegetable lambs or dragons or headless men.
Could it be that the government doesn't know what in the world it's dealing with and is trying to save face? I don't know.
If I remember right, Jacques Vallee seems to think that the government has also been involved in pushing certain narratives about UFOs. For example, I think he believes they were involved in making up the whole Roswell kerfuffle. Maybe I should look into reading more of his work, but his book Confrontations I found so unsettling that I lost the interest to read his UFO works any further. Dimensions I actually enjoyed though.