For the first 30 years of my life buying fresh food was not an option so I never developed a palate for fresh food at all. So I raised my daughter the same way because it that was how I was raised. Up until she was about 15 when I started to make more money and could afford to buy better food. Now I try to eat more fresh food and try to get her to eat it but neither of us can really keep it up for any length of time.
In most cases eating fresh food needs to start young, this is why fresh food in schools and school gardens are so important. And then availability of fresh food through things such as urban gardening would make it easier to continue to eat fresh food. But realistically it would have to be abundant and cheap to even make a dent.