Maybe the fact that nobody was looking for anything of the sort, the clean up operation focused on locating humans ( or remains ) and yet another twisted bit of metal was most probably not at all interesting. The fact remains that there is a HUGE difference between applying loose powder thermite to any given bit of steel, or using a fixture ( that indeed may have been designed to be self-consuming ) to focus the heat against a given bit of steel. In exactly what way should the results obtained by Jonathan Cole be discredited? Be specific.
But it was indeed looked for:
"NIST has looked at the application and use of thermite and has determined that its use to sever columns in WTC 7 on 9/11/01 was unlikely...
To apply thermite to a large steel column, approximately 0.13 lb of thermite would be needed to heat and melt each pound of steel. For a steel column that weighs approximately 1,000 lbs. per foot, at least 100 lbs. of thermite would need to be placed around the column, ignited, and remain in contact with the vertical steel surface as the thermite reaction took place. This is for one column . presumably, more than one column would have been prepared with thermite, if this approach were to be used."
Questions and Answers about the NIST WTC 7 Investigation