Yeah, in principle I'm excited about the PDX-PHL flights, but that very early redeye and the 6:05 AM westbound departure are non-starters for my leisure or business travel in virtually all cases.
I guess it maximizes utilization: that plane is back on the west coast in time to fly morning west coast flights or to operate the conveniently-timed PDX-BOS flight. A sensible redeye leaving PDX after 11 PM and leaving PHL at 8 or 9 AM wouldn't allow that.
Worth noting that the BWI schedule can't be an out and back; they must have planes flying LAX/SAN/SEA-BWI-PDX and vice versa.