I don't think it is just the government acting whacky that motivates folks.
I think some of these folks have a need to feel important and to be breaking the next big story. Just look at all of the wannabee Buckheads out there when something funky comes out and folks are crawling all over the story looking for the one discrepancy that they can get the scoop on.
Others have a scam going, pure and simple, and push these theories as part of that scam.
And others shoehorn these theories into a fatalistic view of what we are going through (not hard to understand, given the nature of many of our current events).
And it all comes together in the self-confirming realm of internet sites where the conspiracy-minded can come together and find affirmation, no matter what their motives. And in that paranoid mindset, anyone who comes along and tries to inject reasoned doubt into that conspiracizing is obviously part of the grand scheme to cover it all up. Which prevents any critical feedback from entering their loop.
What all you said is true. Homeland inSecurity is adding to their ranks more than you understand.