(I hope your not headed toward some truther end.)
The World Trade Center was a fairly unique design, meant to optimize open floor space, much of the weight was carried buy to exterior walls.
This building and 97% of all steel building are braced frames. The World Trade Center was not a braced frame in any classic sense.
You're right about the unique design of the WTC buildings, but that doesn't change the physics of gravity. Remember that a building is designed to handle predictable loads -- the mass of the building and its contents exerting downward forces, and wind loads and seismic activity exerting lateral forces that are typically very small compared to the dead load (building and contents) and live load (people and processes in the building) of the structure. Once the configuration of the building or its structural elements changes substantially (by leaning, for example), all bets are off and it will no longer behave the way it was originally designed.
P.S. — Keep in mind that a toppling building would be subject to rotational forces that it would never experience in its “natural” state. Imagine a 600-foot building toppling sideways. In order for it to maintain its shape, the entire building has to rotate at the same angular (rotational) rate of speed. This means that the bottom of the building is basically turning in place while the top is rotating at a ridiculous rate of speed just to “keep up” with the bottom. A skyscraper could never hold its form under those stresses.