[seph-reed]

You're defining a bad conspiracy theory. Most (but not all) of them are bad. Some of them have been true.

To say all conspiracy theories are bad is to say the government never conspires, or at least nobody ever correctly theorizes about it. Seems unlikely.

[msla]

No, I'm simply using the noun phrase the way normal people use it:

https://en.wikipedia.org/wiki/Conspiracy_theory

and check out the citations.