I'll move for kids to sit with parents, but I won't move for adults to sit together unless they come up with a really good story. "We're together" won't do it. Neither will "We're married." "We just got married" might if the happy couple was nice enough and didn't get snotty. "We're scared to fly and want to sit together in case something happens" would do it because it bothers me, too. Make notes, couples.
And I am very very happy with low fares, no matter what the service is. If I can't afford the fare, even if the service is fantastic I wouldn't know it. I can put up with anything for two hours.