Originally Posted by 787fan

I think the issue is that neither EWR nor ORD serves many Asian destinations either (compared to true TPAC gateways like SFO or SEA, but access to those from DCA is always severely limited.)

Especially if you're flying F or J, from IAD at least you can have international F/J flat bed all the way to Asia/Europe instead of some domestic F trek out to the west coast first.