I can see both sides of this "arguement" as I have seen and been party to a few of the issues discribed. While, I definately agree that the Chicago area has plenty of farmers markets, I don't know of another city that has the number I've seen..just southwest are: (Palos, Orland, Tinley, Evergreen Park, Oak Lawn, etc) However they are usually summer only and 1-2 times per month. In regards to the crux of this arguement I believe is the idea of a large, year-round, PERMANENT market, open daily.
Also, due to the city of Chicago's adversity to street food, largely due to sanitation issues I believe, there has been a perhaps an "over-condemnation". While a youth, I used to work both at the Cal Park concession stands as well as the ubiquitious three-wheel icecream carts that we rode up and down the lakefront. Now, I think they are no more.
I think that the city has decided to over regulate, in a somewhat "Big Brother" way, the consumption of commestibles. I truely believe that if the regulations in place now, had been previously, you would be now missing out on quite a few Chicago institutions we still enjoy. I'm sure Rene G would be the source to more actually advise on this issue, but just from my limited experience (south side) there are a number of endeavors that began on the "streets" and made "legitamate" concerns. Which we will not see again, due to the proliferation of city regulation. Finally, I will add that due to many problems (packing plant issues?), the city had perhaps a less than stellar reputation, and wanted to change the public perception.
Just my two cents...