I think the media and a few superstar teen players have warped peoples expectations. Suddenly everyone needs to be playing like Messi and Ronaldo from 18 years old but in reality it doesnt work like that. A handful of players break through at 18/19 but I would bet the majority are closer to 21+ before they establish themselves.
Players / Agents are becoming more proactive in getting the best for their careers and arnt prepared to wait for a 10min sub appearance once or twice a year. They want to be the next big thing and back themselves to achieve it if they get a proper chance at first team football.
Personally I think we have done a piss poor job of promoting youth due to shortsighted transfers, filling the squad with average backups who were barely capable of standing in for the first team when called on anyway, just a waste of time and money. Would have preferred to see some of our own get a chance, if only 1 of them managed to impress and fight for a place in the squad it would have been worth it over the millions wasted and set an example for future youth players that if they work hard they can get into the side.
Only now have we finally cleared a lot of the deadwood out, it should hopefully mean we supplement the star players with youth rather than sign more average backups.
Its up to us to prove to our youngsters they will get a chance or they will look to move to clubs who will.