This rather condescending article seems to define "conspiracy theory" as something that is always by definition untrue, rather than something that may ultimately be true but is "officially" considered untrue at the current time. It is of course a simple matter to disapprove the notion that all conspiracy theories have been false. Many prove to be true. I remember well when the notion that LIBOR looked manipulated was…
The article is a bit loose with using both interchangeably, but it's clearly about conspiracy theorists - people for whom conspiracy theories are a pastime.
From my own experiences of people who would define themselves this way, this seems to manifest itself in enjoying discovering new conspiracies from the conspiracy theorist community. And, perhaps more importantly, the conspiracies need to stay conspiracies for the most satisfaction. It's not a desire to unmask the truth so that the world can agree and benefit, it's the buzz of superiority from being in an "enlightened" minority. It is difficult to talk to these people about these topics, hence the article.