I agree that there is certainly a history of using these kinds of incidents to enact bad legislation, deprive people of liberty, and otherwise engage in bad activities. That being said, I remember Oklahoma City a lot differently. Despite not being a member of a militia, Clinton used McVeigh's attendance at a militia meeting to go after militias. There were all sorts of investigations and militias were certainly under a great deal of scrutiny. Not that they ever had a great public image, but it was a heck of a lot worse after this.
I don't doubt that there a lot of people out there that hope this is some anti-gov't, right wing extremist, to confirm their biases and bigotry.