Originally Posted by
weero
Because UA cannot show in any way how the OP would cause them expense and harm by not flying on a paid segment.
Sure it can. UA would have lost the opportunity to sell the ORD-MKE and MKE-ORD seats at a higher fare than what the OP paid for those segments.
By not showing up with no notice, UA would assume those seats were taken and would not sell them to someone else (aside from whatever their overbooking algorithms might permit).