I was bitching about it yesterday because I had to pick someone up there, which is like 30-45 more minutes of driving than Midway if I take the toll road (which, you know, costs money), or an added 30-45 minutes on top of that if I don’t.
If I were flying, I’d still prefer Midway, as the layout is less awkwardly sprawling than O’Hare.
To be honest, it’s probably 90% familiarity and proximity for me, since I only use O’Hare maybe 1 out of every 5 times I fly, tops. Every other time I use Midway.