Problem as I see it is that the terms "conspiracy theory" and "conspiracy theorists" are used to pejoratively label people that are against things that aren't actually conspiracies, but are completely out in the open as stated policy objectives of different groups and individuals. The war examples you cite were pretty much out in the open as plausible, yet flimsy pretexts for war. It was pretty blatant to all but the casual observer, the only problem being that most people are casual observers and the mere possibility that Saddam Hussein might still have some chemical weapons around in some storage place was all the justification they needed for going after Saddam Hussein... which of course wasn't a bad objective, just once people spent so much time focusing on WMD more time was spent planning for finding WMD than for how to secure the country after a victory.
Take the whole "NAFTA superhighway" thing which has a wikipedia entry that points out the association of the term with conspiracy theories... but then somewhat helpfully links to the "North American SuperCorridor Coalition" which advocates for the expansion of the "International Mid-Continent Trade Corridor" which are apparently both very real things that exist and have people advocating for them.
So, people that talk negatively about the "NAFTA superhighway" are labeled as conspiracy nuts when in fact they are merely using a different label for something that actually exists and actually is associated with NAFTA .
And to be clear.... I actually support free trade and more normalization of economic regulations between North American, Central American and Caribbean countries. I'm a 19th century manifest destiny sort of guy and would like to see American expansion continue. No conspiracy here. I'd state it publicly that it should be an objective of US foreign policy to seek expansion of the United States among willing democratic partners in the region. I support Puerto Rico's efforts to join the union as a state and if any other Caribbean nations wanted to join I think that should be something we work out and make happen. If Mexico and Canada wanted to join up, which they really really don't, but if they did then the more the merrier.
All that said to underline the point that I mostly disagree with people that are opposed to freer trade or efforts for more economic and political integration. But I do share concerns of some about how we go about doing it and feel that the opposition is healthy and addressing the criticisms and very real downsides to greater economic and political integration, especially through international organizations and treaties, are important.
In the case of NAFTA, calling the opposition to free trade and the "NAFTA superhighway" conspiracy nuts is a really disingenuous attack on people with real concerns about the real negative effects of free trade and in the power of corporations to push through changes to the laws that disproportionately benefit those large corporations. To me the more that people opposed to NAFTA and other free trade agreements are grouped together, labeled as conspiracy theorists and dismissed the more I become concerned that those involved really don't want people looking at the details of these arrangements.
And to me that kind of suspicion is healthy, very healthy. I don't assume nefarious intent, but that doesn't mean that people aren't trying to distract away from some sweetheart deals that might not stand up to scrutiny. So there should be scrutiny. People don't often rise above their own self interests, that is just human nature. At some level, I don't even care about sweetheart deals or even plain old corruption so much as whether or not there is an overall good or bad result that benefits the most people. Nothing good can come of simply labeling people as conspiracy nuts and dismissing their valid concerns.