So they'd rather send a plethora of plane pieces, weighing anywhere from several hundred to several thousand pounds, crashing down onto a whole bunch of major buildings, one or more of which might be a crowded sports stadium? The cure is worse than the disease. Shooting down an airliner over a populated area would create a swath of destruction several miles long. At least when the aircraft is in one piece there's only so much damage it can do.
[This message has been edited by Factotum (edited Jan 31, 2004).]