I firmly believe it's due to the influx of foreign players in England and the reluctance of Premier League teams to give young players that much need experience, either for them to pick up form or even for them to develop into top class players. Rich Pullen made a great point the other day about Germany and how their youngsters from the last World Cup had made so many appearances for their club teams in the Bundesliga. Not so much Henderson because he is playing every week for Sunderland and will only get better, but the likes of Gibbs, Walcott et al need more experience of Premier League football.
I largely agree, but I actually don't think the Premier League is a good place to learn to play international football even if these youngsters do get a game. Sure, top internationals from overseas can come here and thrive - once they have adapted to the pace and hectic nature of our game - but they all learnt to play somewhere else.
He'd earn less money, but it would be great to see someone like Gibbs fuck off to Ajax or Bordeaux or Wolfsburg or Anderlecht or Partizan fucking Belgrade, play football every week in a less pressured environment and get some Champions/Europa League experience.