That makes sense, but you could argue that there is a cost associated with upsetting and frustrating your customers that maybe the airlines aren't taking into consideration. Something can't be right with their models if they are going bankrupt again and again.
Would you prefer that they raised the prices of the Montreal to Paris trip so that you can pay more?
Or do you want them to lower the price of the Newark to Paris trip so that it sells out early and people who would have been willing to pay $1400 for that trip can't get to where they want to go?
False dichotomy. If there are really that many people who want to fly EWR->CDG, but don't due to cost considerations, the airlines will add more flights to fill extra demand caused by lower prices.
If they can charge that much, "theoretically" it means they would make more money adding an extra flight on that route.
They didn't, that means adding an extra flight might have been a lot more expensive. (due to, e.g. regulation limiting the number of planes in that route).
