Depends, I think some states are best visited by a lay over
I have not heard of any redeeming qualities of Illinois so I would say yes...count it. You had to breathe the air, call it good.
You shouldn't have to suffer through a lame state just to say you dun did it yall!!
For me it would depend on whether I wanted to go back.
Airports count, they have gift shops with pictures and special instate products.
...Sometimes just the airport makes you never want to go back. I saw the Eiffel Tower as I was taking off out of Paris, and thats the last experience I ever want to have in France.