Many compannies are cutting back on business travel, with being able to do tela conferencing. It's not just the cost of air fares but you save hotel and meal bills when you take 1 day trips. This is not a issue with say WN all round trip fares are really one-way double.
In our company we have other facilities near ORD so going to MDW is not convienent. Both UA and CO had flights to MDW at one time.