I cant speak as in depth as all of you about state rankings in Illinois, simply because I havent played hardly any of them since theyre all private. The two I have played (Medinah #3 and Rich Harvest) usually take a beating from you guys. My biggest problem with Illinois' rankings is the lack of public courses. Im not saying the public courses are worthy of the distinction, Im saying that while there are some good tracks, theres nothing that remotely moves the needle for me or the raters. Look at Wisconsin! Not only do the cheeseheads make me jealous in football, but its worse in golf! Michigan has better public courses. Heck, Id rather drive 6 hours to French Lick to play the Ross and Dye courses than play anything in Illinois. For as big of city that Chicago is, its a shame we (I) have to go to another state to play a top 100 course. Sorry for the rant.
While I concede there isn't an abundance of true great public golf courses in Illinois, I also think Chicago/Illinois gets a bit of a bad rap. Most of the "great" public golf in Michigan and Wisconsin are resorts as opposed to public access that serves a population, and many exist in part to serve Chicago's population.
There have been some recent additions, like Highlands of Elgin and Bowes Creek that I find very enjoyable, and reasonably priced (particularly Highlands). While I'm not a huge fan of Dubsdred (post Jones), it's a quality course capable of challenging the best. There's some muni's with great bones like Forest Perserve National (Dunne), reasonable upscale daily fee (Prairie Landings, Glen Club) and some under-appreciated layouts that aren't in perfect shape like Heritage Bluffs. Get outside Chicago, and Illinois is home to one of the more enjoyable tour courses which can be played for under $100, and small towns from Belvidere, to Kankakee, to Pontiac to Monmouth and throughout the state have no shortage of nice, if quirky affordable golf that can be walked for about $20.
Most, not all, public golf options that find themselves on top 100 rankings really serve a region more than their local area anyway. While there is likely a shortage of courses that would get lofty rankings on the Doak scale, and it may not make sense to book a trip to Illinois to see it's public golf, I do think there are a lot of courses capable of serving the public to fine experiences.