if subway had a drive thru, they'd take over the world.
Certain ones may get that...but they like to have a certain ambiance...where you can sit down, chill, kids can ride over and chill...kinda like a Starbucks, but it's subs...
Quiznos is the same way...I have met some nice women at quiznos during lunchbreak...just sitting and chilling...the atmosphere at a McDonald's, no matter how much they try to make you feel comfy, is still rushed...
Subway and Quizno's sell the "sit down, and enjoy your meal" ethos.