It is perhaps interesting to note the fact that people within 9/11 truth who decry the marginalizing, sensationalistic, and effectively unprovable nature of controlled demolition (I count myself among these people) can be equated with people within the larger progressive movement who decry 9/11 truth itself for these very same perceived drawbacks. We all have our line in the sand, as Dave vonKleist said.
Many people think that the case for government complicity can't be proven, that's it's outlandish (or sounds outlandish to the "average person"), and that pursuing such an idea is unproductive for real social change. They say, "Focus on the concrete stuff, you don't have to get into all that conspiracy theorizing." They think that 9/11 truth taints all progressive causes. They think there are more important issues and more important information that you should be filling your brain with. It's worth considering.
Controlled demolition theorizing is full of details and contradictory sources that most people don't have the patience for. For a lot of people, so is 9/11 truth. For me, CD is one small, unreliable piece of the puzzle and the technical details seem too far abstracted from the big picture to be worth focusing on. To equate our whole movement to CD is ridiculous and irresponsible.
I'm agnostic on CD and I respect both mark and BrianG's input on the topic. I do wonder what we're trying to accomplish by debating though. Most of us have poured over the evidence at one point or another and we're not likely to change our minds. Are we getting anywhere by arguing these points in 2013?