Well why should they leave?
Delta's regional pilots get to go outside of texas and oklahoma! That alone makes okay to work there by OYS' standard. In fact DCI pilots fly a larger route structure than SWA pilots! Cabo, toronto, vancouver, miami, the bahamas and everything in between!
A senior Delta RJ pilot can cross the entire country in one day!
So since they get to see the whole country and other countries too like Canada and Mexico along with overnights in really cool places like Los Angeles, Seattle, NYC, and Tampa why on Earth would they go work at a place like Delta where they'd be flying the 88 between Atlanta and Detroit?!
Sorry, according to OYS it is okay to make less money as long as you get to go to cooler places.