I've always thought it was a real shame that the Boston Marathon is so mythical, because there's a much more symbolic potential route: start at the Old North Church in the North End (the "one if by land, two if by sea" place), through downtown/the common/Back Bay, then take Mass Ave all the way to the Lexington Battle Green (site of the first battle of the revolution), and that's almost exactly half a marathon in distance while more-or-less reenacting the Midnight Ride.
An otherwise unmotivated position sustained as desirable only by the difficulty generated by the number of people trying to crowd into it serves as a deeper representation of this country than the story you're proposing to replace it with. ;)
