Kevin Beachy describes simply the two parts of the collapse.... Upper part "loses integrity/support" and falls the intact floor slab below which can't support these loads. This begins the rapid floor slab collapse one after the other.. Columns did not collapse with floors... but as a consequence of their losing the lateral bracing required for them to stand. Columns needed floors for strength and stability... floors needed columns to hold them "up". Floors went first columns had to follow.Isn't this forum about how to explain things to (i.e., debunk) conspiracy theorists? Telling someone who is genuinely curious/puzzled about how the buildings could completely destroy themselves that "no one cares" isn't very effective. Besides, engineers do care about progressive collapse and do see WTC as a prime example. For example, as I mentioned above, Uwe Starossek.
The NIST report may have completely satisfied you. But it obviously didn't close the question for everyone; and research, like I say, continues to this day. There's a government report on the 2008 financial crisis too; but that doesn't mean people aren't still writing books about it.