Most press events are orchestrated well in advance of the day in terms of personnel invited. Going into the race, Dryer was def. US champ and a prerace favotite. And Browne, aslo a prerace favorite, was a past Olympian (perhaps the only male one in the field?), and that is media-friendly. As has been said many times, the general public (who buy a lot more newspapers than you guys) will take much more notice of runnign when the word "Olympic" is used.
Alternately, perhaps those 2 were the only ones who could be corralled to the press conf., or perhaps would be gracious enough to go to one. You've never seen a football player blow off everyone to go for a postgame 3-mile warmdown, have you? Runenrs disappear like that all the time.
But then again, this is LetsRun.com, where, unless runners are paid like Peyton Manning and featured for the first 20 minutes of SportCenter, it's USAT&F's fault.