As a former cyclist, this analogy doesn't apply because the bikes are most likely going 30-40 mph below the posted speed limit.What difference does it make if they take up the whole lane? You should be going all the way in the other lane to pass them anyway even if they are single file. Do you pass a motorcycle while staying halfway in his lane? Sometimes on really narrow roads cyclists take up the whole lane exactly for that reason, to keep cars from passing too closely and shoving them in the ditch. Believe me, it happens. Cars think they can squeeze by a line of cyclists even with a dump truck coming the other way. They are so important that they can't wait an extra minute or two to get by.
Taking up the whole lane with bikes, especially around curves, is just as inconsiderate and suicidal as if you were doing 15mph in your car on a 45-55 mph country road.