[scalziand]

It is harder to hit a smaller target. Plus, there is the possibility that not all the plane's kinetic energy will go into the tower since parts of the plane won't actually hit the tower. I suppose it's possible to fly the plane rolled 90 degrees vertically into the tower to ensure maximum damage, but I find that pretty improbable for a hijacking scenario.

In the case of 432 Park though, I would expect that the solid high strength reinforced columns hold hold up better under that type of impact than the hollow tubes used in the WTC. Tubes crush pretty easily relative to their axial strength, especially under a lateral point load concurrent with a compressive axial load. Not to mention the concrete will be far more fire resistant. 432 Park also has many more transfer levels than the single hat truss the WTC towers had.