Of course it does.
So let me ask it another way: can the OP find those on a tour?
From his/her post, I sure don't think so.
I am going to be blunt and completely honest... One of my jobs is photography, and one of my hobbies is photography, therefor I want to see DC through the viewfinder. I tend to pay a lot more attention to details and notice shapes and colors more when I am setting up shots. I would miss the same things if it were not for the camera. And to put a point on it, I am going FOR the photography, mainly architectural, the history bores me. Take my cameras away and I have absolutely no reason to want to go.
The reasoning for the tour is simple. I get to see a lot of places, all the transportation is taken care of, and since it is a photo tour, I don't have to worry they will walk away as I am setting up a shot or get annoyed having to wait on me. Am I there for the postcard shots? Somewhat, just because they have been done a thousand times does not mean I don't want to do them too. But I am also there to get my angles, my crops, my vision of the same thing other people have captured.
I sincerely believe I could do the same thing on my own, with a couple of problems. 1) I would never be able to get to that many places in that amount of time since I have never been before. 2) I doubt very seriously any security will have a problem with me lugging around a camera in Union Station or somewhere else I have heard of problems with photographers if I am with an established tour group. 3) I have exactly two days to get in all that I can. Day one is all tours, day two is exploring on my own.
Now if you have a better solution to cover more ground for the same or less money in the same or less time and be assured of getting to the prime photo locations, I am all ears.
Allan