I was thinking a lot about the relationship between these two today as I was trying to nail down a parts list for the first Longleaf custom. Of course, many bikes combine both of these uses, and often one bike ride can be for both uses--but if we think of them as two poles of bicycle design, its a nice lens though which to see the bicycle. I'm using "sport" in its broadest sense to include not just competition, but any type of recreation.
One of the first Longleaf frames made will be built up and sent to Jan Heine of Bicycle Quarterly so he'll ride it and hopefully review the bike in an issue. My plan is to build the bike up for myself, but I found myself considering how certain component choices would be received by the randonneuring-centric BQ staff.
I don't have much time for randonneuring--maybe when the child and children to come are older and the business is more established I will. So I definitely don't critique bicycles through that lens, or any sporting lens, because the bicycle to me is always first and foremost a vehicle for transport. But if any sporting use of the bicycle combines well with the bicycle's utility, it is probably randonneuring. Randonneuring requires riding on varied surfaces at all hours of the day and in all conditions. I've done a brevet or two, and wouldn't call myself a randonneur but I find myself drawn to the bikes because they also make very good vehicles.
There is a kind of twin heritage of bicycles--they were made for transportation and first raced as a way to demonstrate to a (at the time skeptical) public that they could swiftly carry riders over great distances.