Of the traditional big four, we're giving more game time to youth players than anyone at the moment. Over the last ten years we've been the most successful club in the youth competitions (U21 league, Youth Cup). The Premier League is absolutely riddled with former Manchester United youth players - I read an article on the topic a year or two ago, can't remember the actual numbers but we're ahead of everyone else by an insane distance. We're producing an ever-greater density of talents like Welbeck, Januzaj, Lingard, Wilson, Pereira - and only recently are these kids regularly getting the chances necessary to demonstrate their talent and potentially make their way into the first team, which is an incredibly difficult thing for clubs with trophy ambitions to do, more now than ever.
Oh, maybe the players just aren't that good and that's why they weren't getting chances in the team until recently?