Originally Posted by
nineworldseries
People post all the time on FT about such supposedly "underserved" routes. eponymous_coward has it spot on. Airlines, I'm assuming, spend a lot of money on yield management to figure out exactly which routes will be profitable for them. If you thought of it, they also have before, I guarantee it. It's not like someone at AS dropped the ball here, and they'll be like, "oh crap, we forgot to fly to Detroit!"
Not only that but being that PDX is an AS hub and DTW a Delta one, with the ongoing turf battle between them, AS has most definitely considered this route but for whatever reason, decided not to start it.