Having a 4 year degree is also deemed competitive with foreign carriers such as Etihad and Emirates. Not sure about European and Chinese carriers. I believe that Cathay Pacific values it as well. The reason that it is so cherished by the U.S. legacies is because for every single pilot position available, there are twenty pilots (hyperbole on the 1 to 20, but the odds are certainly stacked against pilot applicants in the U.S.) vying for those slots. Remember it isn't only regional pilots competing for the legacies, but many military, part 135, LCC, ULCC and ACMI pilots too...not to mention pilots from foreign carriers who are returning to the U.S. to work for them.