And even then one only just hit it.True, but the WTC towers probably didn't look very big until they got very close, either.
And all, basically, at ground level. Misjudge your angle of approach even slightly and you'll miss it completely.I imagine that some HV/EHV facilities cover at least as much ground area as one of those towers.
With a large passenger jet It would be a very difficult target to hit (more difficult than a tall tower) unless you were a very experienced pilot and had the benefit of a long approach. You won't get much of an approach flying at low altitude so you would need to be "lined up" at around a minimum of 2500 feet I would think. A runway is narrow but its long and pilots do not always land near the start of it. Sometimes touching down quarter of the distance in (and thats with a nice gradual decent, lined up several miles out)