You're pretty hard on Boeing for not using a canard design. Actually, there are some very good reasons canards don't work well as transport airplanes. These are:
1)If a canard configuration is to have the same lifting area (canard and wing) in cruise as a conventional design (wing and h. tail), the canard configuration will need to have the same high lift devices fitted on the canard as the wing. In fact, the canard high lift devices will probably need to be more extensive than the wing. Therefore, the canard will be more expensive to build and maintain. The conventional design needs only wing high lift devices.
If you don't want to have high lift devices on the canard configuration, it will need more combined lifting area than a conventional design to have the same low speed performance. More lifting area means higher skin friction drag for the canard configuration in cruise and lower economic performance.
2)Canards are more difficult to load than a conventional design and have higher induced drag.
Consider that on a conventional design, all payload (passengers, cargo and fuel) is distributed about the wing center of lift. Usually, the C.G. is near the center of lift and tail lift up or down is relatively small. This allows the wing to produce most of the required lift and minimizes induced drag. As the fuel in the wing burns off, the C.G. position and tail load remain relatively constant, so induced drag remains relatively constant and relatively low.
For a canard, all the passengers and cargo are ahead of the center of wing lift and the fuel is near the center of wing lift. At the start of cruise, canard and convential designs may have nearly the same induced drags since in both cases the wing is producing most of the lift. As fuel burns off for the canard configuration, the C.G. must shift forward. This will unload the wing and load the canard to maintain trim. Since the canard span is less than the wing, induced drag will increase and be higher than a conventional design.
Economically, a stable canard cannot compete with a convential airplane due its inherently higher skin friction and induced drag. An unstable canard would be more competitive, but the regulators and I suspect most pilots aren't quite ready for that.