I've never noticed any Saab 340s, Dash 8's or EMB120s at ORD. Is this because of the potential for heavy winds/winter weather? I feel like winds can be a big issue at LAX/SFO and the Dash 8's fly many of the routes into ski resorts in Colorado.

All of the other domestic hubs have props...but none at ORD (as far as I can tell)!
LAX - EMB120s
SFO - EMB120s
DEN - Dash-8
IAD - Saab 340

Any insight into why this is?