That's because it tastes like @#$%

I have always thought that a fast food restaurant focusing specifically on healthy foods would be tremendously successful.
Whole healthful foods, not processed foods with everything taken out of them for marketing purposes, such as the examples given above.

Pure, unadultered vegetables, fruit, lean meats, grains, beans, and dairy would provide excellent options for consumers. Using herbs and spices to create tasty meals would be ideal. No grease or trans fat oils.

I frequent grocery store salad and soup bars all of the time to create a great meal for myself.

I love how Subway offers yogurt and apple slices as options for sides if you buy the meal option, as opposed to only including chips and cookies as meal options. I really wish more fast food joints would follow suit and offer fruit, yogurt, or a low salt soup as a side option in place of french fries. Not everybody likes shoe string french fries.

The free market solution is to incent better health by promoting that consumers are more self-responsible
& pay for their own routine health care through health savings accounts for example & therefore eat healthier (or pay) rather than by govt program "persuasion".

Does that mean it's time to short the Mc Donald's stock? Just kidding.
I think consumers associate each fast food chains to a certain diet style. Mc Do is known for burgers and French fries so if people want that, they'll come to Mc Do. If consumers want healthier sandwiches, they go to Subway because they are known for fresh, healthier meal options. This is why Subway has the most diet conscious eaters.

Evolutionarily, most mammals are programmed to seek out fat, sugar and salt, which are at a premium in nature. Only in the last 50 years or so of human existence have these become ubiquitous in a few countries, such as the United States, and have even more recently been available more cheaply than healthier foods. So it is no surprise that we are gorging on them and having health problems. That and a much more sendentary existence.
In any case, we can't blame people for eating what we are programmed to eat.

The reason for this may be explained by the fact that people who are concerned with eating healthily do not often choose to purchase food from places who primarily serve unhealthy food. If someone wants a burger and fries, they'll go to a burger and fries place. If they want something healthier, they probably know where to look. Even if I knew that McDonalds had a "healthy" menu I still wouldn't eat there because "healthy" means more than "low in transfats." It means fresh, seasonal produce, balanced carb/fat/protein/fiber ratios, and whole food that has been minimally processed.

Healthier fast-food chains like Subway and Chipotle are thriving, indicating that many consumers DO care what they eat.

"Little Caesars has pizza crust and sauce with no animal products." Does this mean that most chain pizza crust and sauce DOES contain animal products? *Shudder*

Turkey Burgers have exceeded expectations at both Carl's Jr and Hardees, and they are excellent !!!