Here are a few:
Insurance $$
$$ to remove and replace lots of Asbestos from these old buildings no longer needed.
Thousands of documents related to criminal and SEC suits destroyed (of which Enron and Worldcom formed a part)
WTC 7 had offices for:
CIA
DOD
IRS
SEC
Secret Service
Various Banks
Pentagon not able to account for 2.3 TRILLION (as of Sept 10,2001) missing that was being investigated at the time
Lots of "coherent" reasons if you bother to look rather than mock.
You have bad information. Allow me to give you some better information.
Asbestos removal had been going on at the World Trade Center since the late 1980's. I don't know how much you know about asbestos, but basically, it's safe as long as it's not in the open air and being breathed in. Therefore, you only remove the asbestos if it's being disturbed because of further construction. Obviously, tenant alteration work was always being performed in the WTC due to tenants moving in and out, leases ending, companies wanting to renovate, etc. One of the things that had to be considered on a tenant alteration application was whether asbestos-containing material (ACM) had to be removed. If it did, an on-site contractor who had a contract with the Port Authority, owner of the buildings, came in and did their thing with all the encapsulation and the licensing and the proper disposal and manifests and whatnot. And this on-site contractor kept his offices at the WTC because there was always tenant alteration work in process and there was always ACM removal work in process. Tens of millions of dollars were spent on asbestos removal in the decade prior to 9/11, particularly because the buildings had become attractive as a downtown address and higher-class firms were moving in. The buildings, as you probably know, were at 95% occupancy at the time of the attacks, virtually full in the commercial real estate world. To say that the PA knocked down their biggest asset and took on a century of lawsuits because they didn't want to spend the relatively miniscule amount of money to remove any more asbestos is, frankly, an ignorant thing to say. I don't know how else to put it. It boggles my mind that someone would actually think that.
Now as to the silly insurance thing, I've no doubt that people who believe that the buildings were knocked down to gain some phantom insurance profit are the same types of people who drive their pickup trucks into the local creek and then collect a check from GEICO. But in the commercial real estate world of the largest city in this nation, it just doesn't work like that. Simple basic facts: The net lease REQUIRED the net lessee SPI (Silverstein Properties, Inc.) to have insurance in case the buildings were destroyed. This destruction could have happened by earthquake, by hurricane, by terrorism. It WAS a known terrorist target, as anyone with half a brain was aware, and had been hit once with supporters of the first attacks swearing they would come back and finish the job. So, of course the net lessee is required to have this insurance. That is a no-brainer.
And of course, the insurance underwriters are going to include language that any insurance payouts in the event of a destruction are going to have to go toward rebuilding. Another no-brainer. So, after court battles with the 11 underwriters, SPI gets a payout of $4.6 billion TO REBUILD AN $11 BILLION PROJECT. I don't get the lack of arithmetic skills that are making everyone so confused about this. The numbers are very simple. There are just a lot more zeroes.
Under the Master Agreement with the PA in 2005, Silverstein had to turn over part of the insurance to the PA because the PA could issue bonds to get One World Trade Center's building started. Silverstein started to rebuild his portion at the site, but then the economy took a nosedive. Now, if you've been paying the most cursory attention to what's going on at the site at all, you would know that while SPI has Four WTC almost built, the foundations of Two and Three are all that exists, because he can't get financing due to not being able to guarantee that he'll have any tenants in this economy. This is all very public information, easy enough to find on the Internet.
There are a whole lot of REALLY SMART PEOPLE in the New York City commercial real estate industry, and they aren't running around thinking that the PA and/or SPI demolished their own buildings for asbestos or insurance or any other lame reason that people living in the boonies with wild imaginations and YouTube videos think. I suspect that most of the people who come up with these tales live in places where the biggest building in town is four stories high. There is nothing wrong with living in places like that, but there is something very wrong with choosing not to be informed.