Because it's not a useful term. It's a piece of political jargon used to dismiss an idea as crackpot. It's meaning isn't specific and will change depending on

Because it's not a useful term. It's a piece of political jargon used to dismiss an idea as crackpot. It's meaning isn't specific and will change depending on who's using it and in what context. I'll weekend my understanding, if I hear a definition of conspiracy theory that doesn't contain an ad hominem assessment.