Well, okay. McDonald's is really unhealthy. Well, in truth, Wendy's is only marginally less so.
Is Wendy's actually more healthy than McDonald's, at all? This isn't at all clear to me on the face of it. Wouldn't shock me to learn that the average meal sold at Wendy's was less healthy than the average meal sold at McDonald's.
But I can afford to go someplace better. Maybe one of those restaurants like Chili's, which includes "appetizers" that exceed a nutritionist's recommended caloric intake and more sodium than a person ought to receive in a day.
Yeah, restaurant food in general is super unhealthy (and delicious). The thing with McDonald's is that it's cheap and fast. To be honest, I've long thought that there was something of a classist aspect to the McDonald's criticism. That's visible in the lack of criticism of places farther up the expense continuum, but especially salient, I think, in the absence of criticism of "hip" street food, taco shops, etc. Maybe it's just the region I live in, but I can think of a dozen cheap places to eat that are vastly less healthy and closer to me than the nearest McDonald's, just offhand.
To be certain, there is a relationship between consumer expectations and marketplace availability, but there also comes a point when consumer expectations are shaped by marketplace availability.
There is, but McDonald's is not particularly the problem in that area. McDonald's is far, far more responsive to the periodic demands for healthier fast food options. They go through a routine cycle every 5-10 years where people start complaining about obesity and ripping on the biggest visible target - McDonald's - and so, being incredibly averse to negative publicity, they launch a new menu of healthy foods in response. And sure enough, nobody buys them and they disappear after a while. This cycle has been repeating since at least the 1980's (the McLean sandwich), and by now McDonald's is well aware of it and does not expect these products to succeed as such. They fund them simply as a marketting/PR exercise - it gets the media off of their back, and makes people feel better about going to McDonald's (where they proceed to overlook the healthy items and order the burger and fries that they came for).
Meanwhile, the other fast food chains have noticed this cyclical trend, and capitalize on it by breaking the opposite way. Every time McDonald's goes into an eat-healthy PR phase, competitors like Jack in the Box, Carl's Junior, etc. respond by advertizing even bigger, unhealthier burgers (as McDonald's did away with the Supersize Meal, Carl's Junior came out with a line of ever-more-ridiculous "6 dollar burgers" - things like a burger with 2 1/3 lb. patties topped with an entire serving of gyros - and hired Paris Hilton to appear in the ads in skimpy clothing). So the result of the crusades against McDonald's, is actually that customers are diverted to McDonald's competitors who provide even less healthy food, and obesity actually gets
worse.
I would suggest that while consumers shape the marketplace, they only do so within certain parameters; that is, they shape the marketplace within the boundaries it sets itself.
True enough, but McDonald's is not the problem when it comes to setting those parameters. If anything, the opposite. McDonald's isn't interested in anything other than making money, and they've tried to push healthier foods many times, so if there were money to be made there we wouldn't be having this conversation.
Which is to say that your analysis makes sense, but not as a criticism of McDonald's - or even, any other restaurant in particular. It's a criticism of the marketplace as a collective. One of the mechanisms that causes McDonald's' repeated attempts to market healthy food to reliably fail, is that their competitors double down on unhealthy food whenever they do so. There is no single player in the fast food marketplace - not even the mightly McDonald's - that is powerful enough to move the parameters on its own. It takes a collective action which, in the context of a free market, means regulation. The recent requirements to clearly post calorie totals being exactly such a step.
At some point, we have to look at the marketplace.
HFCS isn't a marketplace thing. It's a subsidy/tarriff thing. This isn't the free market, but statist intervention. We had a free market in soda pop for a long time without HFCS becoming predominant. It was only after the programs of explicit government subsidy for corn, and tarriff on sugar, that the current situation arose. It's a policy question, not a market issue.