Two issues: LAX->SFO->PDX isn't an equivalent product if you're going to SFO -- the airline can rebook you on any of a number of options (in case of weather, c

Two issues: LAX->SFO->PDX isn't an equivalent product if you're going to SFO -- the airline can rebook you on any of a number of options (in case of weather, capacity, mechanical difficulties or whatnot) that may or may not go through SFO. Adjusting routing is nontrivial. Planes are expensive. Gate rental is expensive. Pilots are expensive. Getting pilots and planes to where people are with routes planned to haul them to where they want to be is complicated. As an example of how complicated (and fragile) this is, watch the United departure board when there's a decent storm brewing in Chicago -- It's not just the flights going into and out of ORD that get screwed up -- it's pretty much every flight in the country.