I used to be a frequent flyer in two airlines and not just silver elite. I wasn't as much as real road warriors that are flying to 2-3 destinations a week, though.
DL's lack of loyalty has made me reciprocate. Before, I flew on Delta unless the fare was outrageous or the schedule lousy and then I would fly United. Not anymore. The basic economy fares were a big part of killing loyalty both ways. United and Alaska still award some miles for basic economy so they are now my preferred for all travel, basic and non-basic. This is kind of too bad because I am almost a Delta million miler but not almost for United. I don't boycott Delta but they are tertiary for me now.
Strange. On my return SEA-DFW flight Alaska didn't reward me any miles when I booked basic economy/saver, even when I spend for meals, baggage, and seat.