I don't think there are any more magical lucrative routes out there. There are multiple airlines to choose from and more companies have a "buy the lowest fare in coach" policy. While some corporate travelers have unpredictable schedules, there are many who have predictable ones. So why spend $4000 when you can spend $800. This is what is hurting the airlines.

The only magical lucrative routes AA seems to have are RDU-LHR and SJU-CCS.