What is the meaning of "flung their hands up" in this context?

Question

This is the context:

the multiverse is just an example of a bad theory. The multiverse theory can predict nothing. But can it accommodate anything? Oh yes. It can accommodate everything because it is a multiverse and one can find the right place in the multiverse. It’s a remarkably imprecise theory. The amazing thing is that people have welcomed it. They should have flung their hands up.

I searched on the internet and just found one explanation from the Cambridge dictionary:

to show that you are very shocked or frightened.

Is this definition applies here?

Answer 1

This looks like a non-standard use to me. The phrase "flung theirs hands up" (or close variations) is a cliché - or actually, it's a part of a number of different clichés.

You may read about people flinging up their hands in supplication, in horror, in defeat, in shock, in celebration, etc.

It tends to have a literal meaning, describing a gesture (or perhaps different gestures) of raising ones arms, typically with the fingers straightened, or outstretched - as if waving at someone.

In this case, it seems to be used metaphorically, probably standing for they should have been disgusted, or frustrated (which they could have shown by throwing up theirs hands in disgust, or frustration).

It's fine to use non-standard metaphors (preferred, really), but the problem here is that there are so many common variations of the phrase "flung up ones arms" that we don't know which one is being referenced. I'm guessing that the author meant flung up their hands in disgust or frustration, but it may as well mean in horror, in shock, in joy.