It's not because it us "against the norm", it is because the theory itself clearly involves a conspiracy.
No, it's the theory that it is a conspiracy, or more likely, a cover-up. (As I doubt there was a conspiracy to release the virus).
"Conspiracy theory" has a specific negative connotation, and has "specific characteristics ... such as an opposition [to those] who are qualified to evaluate its accuracy." [1]
> A conspiracy theory is an explanation for an event or situation that invokes a conspiracy
> A conspiracy theory is an explanation for an event or situation that invokes a conspiracy by sinister and powerful groups, often political in motivation,[3][4] when other explanations are more probable.[5][6]
And the distinction is clearly drawn.
> A conspiracy theory is not the same as a conspiracy
Now we know that there were GoF research proposals by the same scientists squashing these ‘conspiracies’. Wups conflict of interest.