The road patterns were different back then (they changed them specifically because of 9/11), but if you've ever been near the Pentagon, it's pretty obvious: it's a low building, nestled in a bowl-like land formation, there aren't many good places to sit and "observe" it, and it's surrounded by highways. Most of the time, if you are looking at the Pentagon, you are probably also driving.
And this is 2001, so any tourists driving on those highways were almost certainly holding paper maps and arguing intensely with their passenger about which exit to take to get into DC. They weren’t holding their analog camcorders.
