We live in a capitalist, consumer-oriented society where we are blessed by choices. We have healthy and unhealthy choices everywhere. Most people would be attracted to the unhealthy choices by default, but that doesn't mean we should blame the system. The system also makes healthy choices copiously available.
So while McDonald's is everywhere, we also have In-N-Out Burgers and Chipotle everywhere. Supermarkets with healthy choices are everywhere too. It's a win-win situation for both the health-conscious consumer and the junk food enthusiast.