The average age of the Japanese team is 29 years old (Min 3 apps) so that entire Japanese team won't be there next cycle, I'm not going to break down all the young players the US has in Europe, you can do that yourself by just looking at the call-ups for the past 3 friendlies, the talent is there they are just young and haven't had a chance yet but they showed well in those friendlies against Bolivia, Ireland, and France.
The US is in transition, lots of old players hanging around but we have an influx of new talent most don't even know about. They should have never let Jurgen go, he got us to the Semi's of the Copa Centenario and got us out of the group of death in the 2014 WC, US Soccer panicked and Bruce Arena's horrible tactics are a big reason we aren't in this tournament.