They're probably not scrap metal, probably just sitting out a lease or waiting on a buyer.
I'm still in shock over the UAL thing because any flyboy in his right mind on the west coast wanted to work for UAL back in the 1990's. The biggest jets, the best bases and the largest network.
Heck, one of my pals over there who was there for 5 years as a junior SFO A-320 captain where I was a junior MD-88/90 FO thinking that it was "cool" to fly west of DFW instead of doing the DFW-SHV-MLU-ATL shuttle. Even one of the guys that ditched Delta and went to UAL spent a year as 737 FO and then onto 777 international FO.
Ebb and flow.