Because when it becomes obvious someone is willfully blind to the answers, asking the same questions and ignoring the answers about 9/11 marks a person as willfully ignorant. The studies and reports on WTC 7's collapse started in 2002, the NIST published its final report in 2008. In Tucker's case, along with every other big name TV journalist, after all this time after 9/11 they should already know those answers. If they don't like them, then should have some specific rebuttal other than a vague I don't get it, so there must be something there.
Tucker is talking with Clayton Morris who fled the country to avoid real estate lawsuits. Something about known by the company you keep comes to mind.
Building Seven was built using the steel beams and girders transferred the weight throughout the entire structure. Steel has two properties when it heats up, before it melts. When steel heats up, it gradually loses strength and expands. This why thermal expansion can buckle railroad tracks.
(Am I one of the few Americans left who ever watched a blacksmith heat metal red hot and understood what was happening?)
After the twin towers collapsed, 20 floors in WTC 7 caught fire simultaneously. There was no water pressure left to run the fire suppression system. When WTC 7 was designed no one was designing buildings to have over 20 floors catch fire like that. The steel across all those floors were heating up, losing their individual strength, expanding and putting pressure on surrounding members.
The result was, in simple terms, WTC 7 popped like a balloon.