Here's a great movie that I loved on the subject:
I'm not sure if this has something to do with the building codes in suburbia that require a sprawling parking lots for every restaurant. In South Korea, for instance, there are mom and pop restaurants in every city that serve fresh, delicious food (chain restaurants do exist, but are not as common).
Americans drive themselves around a lot, both for work and for other reasons. When you're looking for something particular or easy, it helps to find a chain location you've had consistent success at.
My theory is that something like Yelp (but with less work to use) would help disrupt this quite a bit. Perhaps Yelp has already helped a bit. I know I've gone to some local places I wouldn't have otherwise because they've had good ratings.
After all, most people like fried foods and meat and things that are, strictly speaking, unhealthy. But historically they've been rarer. Meat is still kind of a luxury in rural China, for example.
And yes, buildings codes require sprawling parkings lots for every restaurant. The people are going to drive there anyway. The codes are meant to require that businesses invest adequate resources in parking so that they don't negatively impact other businesses, street parking, neighborhoods, etc. I don't particularly like it (in fact, I think they should be required to have sidewalks in every row of cars so you don't have to worry about getting run over walking through one), but there you are.
People say "location location location!" and sure it's important, but I bet we can all think of some local "must-eat-at" restaurant that's in bumfuck nowhere and yet still always has a line round the block.
Houston - Moon Tower - Various exotic sausages in house-made pretzel rolls. Amazing, and stuck deep in the old warehouse district. https://goo.gl/maps/2oussCLAe242
Vegas - Cornish Pasty Co - Incredible and authentic cornish pastys by a restauranteer with a sharp tongue but great taste. Not exactly in the middle of nowhere but well off the strip https://goo.gl/maps/UMx8vuov8m32
etc
Manhattan has a weekday lunch time population of about 4 million (about 6500 per idealized square city block) and a dinner time population about half that. And many of those people are quite rich. That leaves a lot of room for obscure niches to be profitably served. In most places business owners don't have the luxury of being able to target so narrowly.
"The cafe has 192 locations nationwide, including in Miami, Los Angeles, San Francisco, San Diego, Chicago, Houston, San Antonio, Dallas, Austin, Philadelphia, Pittsburgh, Atlanta, Denver, Salt Lake City, Phoenix, Tucson, El Paso, Baltimore, Washington, D.C., Tampa Bay and Buffalo metropolitan areas, as well as in Northern California, Mississippi, New Jersey, Virginia, Savannah, East Texas, the Rio Grande Valley areas, and a location in Carmel"
https://en.wikipedia.org/wiki/Corner_Bakery_Cafe
Likewise, Panera has lots of salads and half sandwiches available and 2,000 locations.
Maybe they're "crap" to you? But most people don't eat as well as that, on average, quality-wise.
If all that's not fresh and healthy enough, it's not hard to pick up an (unsauced) grilled chicken breast at a BBQ place and some fresh veggies at the grocery store.
I mean, maybe you have especially refined taste, but all those places aren't unpalatable to the median person.
Before I moved to New York, I used to eat at Panera all the time. I wouldn't say it's bad, but... honestly, I would never eat at one in NYC, because there's basically always going to be a better and healthier restaurant nearby. (Incidentally, there are very few Panera Bread locations in NYC, and they're almost all clustered along Lexington IRT stops.)
Nobody said anything about "Manhattan below 96th". But it's definitely true that, outside NYC (and especially outside the NYC metro area), the options for good-quality, healthy food are pretty rare.
I very intentionally said "New York", not "Manhattan. I would take the options in Jamaica, Queens over Columbus, Ohio any day.