Why are there so many BYOB restaurants in Chicago?

I recently arrived in Chicago from San Diego. Why are there so many BYOB restaurants in Chicago? You never see that advertised in San Diego.Why are there so many BYOB restaurants in Chicago?
Per capita there are more bars and restaurants than there are liquor licenses available. Also, sometimes the owner has a felony criminal record and cannot be granted a liquor license. I think it's a cheap way out for some owners, however, they don't realize how much revenue they are losing in the long run. And what about the BYOB places that charge a cork fee/bottle fee/service fee? That seems like a bunch of crap to me. They make you bring your own then charge you to open it. Almost seems illegal....at least unethical! Welcome to the windy city by the way - the most beautiful city in the world!!!
It's cheaper for the bar to have people bring their own booze.

Things like that start in the east and move westward.Why are there so many BYOB restaurants in Chicago?
a license to sell alcohol is harder to get in Chicago than alot of places. It's easier to have a BYOB. They are all over, even in downstate Illinois.