This is my opinion, and its only an opinion why I think there is a cover up
and the commission is not qualified.
The number one reason is the crime areas (WTC, pentagon) were removed very fast.
Do you remember TWA flight 800? They reconstructed the entire plane with the parts in a hanger to find the problem.
Now im not saying they should have reconstructed the WTC but they should have taken all the metal out to a hanger and done a proper investigation on it. All of the remains were shipped off to china for scrap.
Looking how fast they cleaned up WTC7 and the towers tells me there is a cover up. Someone didnt want anyone to do a proper investigation.
The only one that has done any real tests on the metal is Professor Steven E. Jones. Someone at the WTC took samples and sent them to Professor jones and he found thermite all over it. Thermite is used to cut thru steel.
http://www.physics.byu.edu/research/energy/htm7.html