Why would you look for something when there is clear evidence it did not occur?
External Quote:
...Video evidence also showed unambiguously that the collapse progressed from the top to the bottom, and there was no evidence (collected by NIST or by the New York City Police Department, the Port Authority Police Department, or the Fire Department of New York) of any blast or explosions in the region below the impact and fire floors as the top building sections (including and above the 98th floor in WTC 1 and the 82nd floor in WTC 2) began their downward movement upon collapse initiation.
In summary, NIST found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives. NIST also did not find any evidence that missiles were fired at or hit the towers. Instead, photographs and videos from several angles clearly show that the collapse initiated at the fire and impact floors and that the collapse progressed from the initiating floors downward until the dust clouds obscured the view.
from the
NIST FAQ
Other things they did not look for: moleman activity under the building, death rays from space, steel eating bacteria or nano-dissasemblers.
You seem to think that you (or anyone) saying "oh but I think there might have been thermite" or "I think that you should have tested for thermite or other explosives" is sufficient to require more investigation than WAS done.
I got news for you - it isn't. A crackpot theory based on paranoia, flimsy evidence and wishful thinking IS NOT worth as much investigation as real causes.
External Quote:
All opinions are not equal. Some are a very great deal more robust, sophisticated and well supported in logic and argument than others."
― Douglas Adams, The Salmon of Doubt
or, put another way - sure you are entitled to hold your opinion, but you are not entitled to have it treated as a serious candidate for "the truth" - that is something you have to earn.
and you haven't.