Salads are time-consuming to eat.
Maybe it says something about modern culture, but the darn things simply are not fast to eat! I think I could've eaten a sandwich in half the time it took me to eat my salad. Maybe a third of the time. But its simply not a very "efficient" way to go if you're pressed to eat within a short amount of time. Be it fresh or fast food, there are a wide variety of foods that can simply downed faster than a meal-sized salad, that are just as satisfying, and can be had for the same price.
One could go with something plus a side salad, but I don't see the point. Side salads are nice, don't get me wrong, but honestly as small as most of them are the veggies would be better off getting assimilated by the main course. Instead of those (admittedly cute) cherry tomatoes, just cut up a good-size tomato and add it to a burger, sandwich, tacos, burritos, whatever. Lettuce? Same thing, although I personally consider the stuff to be mostly a speed-bump - spinach would be much better.
I think the other thing is that salad simply isn't travel friendly. Not only does it require being kept cold until serving (generally speaking), but you can't really eat it on the go. Through years of commuting I've gotten reasonably decent at eating in the car, and you simply cannot do that with a salad. Picking at it doesn't work. Fries? Anything contained by bread and a wrapper? Or just cut-up veggies and fruit? Nuts, even? Far better. But not so for salad. Once you add salad dressing the problem only gets worse, and honestly all the dressing is in some cases is a cover for a mediocre salad to begin with. Blah lettuce and tomatoes only made serviceable by salad dressing, with any redeeming value they might have had drowned out under the flood of Ranch, Thousand Island or whatever else you have on hand.
Its a bit annoying of a realization, but at the same time it at least lets me know when salad is best enjoyed; when I've got time and I've got something of quality. Sounds more like a dinner meal to me in this case - to be dined upon after the day's work has passed me by and I don't have to rush through the meal or any company.