Developed being the operative word. Unfortunately there is a significant number of fans, and not just of this team, who give rookies a month or so to start producing, and then start shrieking about what busts they are and how they need to get rid of them if they aren't producing. What they apparently don't understand is that most these players have spent their lives being the best player on the field, and operating in vanilla offensive and defensive schemes, and are suddenly put in a situation where everyone is as good or better an athlete and football player as they are, and the schemes are really complicated and loaded with adjustments they have to make on the fly. And unlike almost every other team sport there is no minor league they can drop down to get acclimated to higher levels of play, they either make it or they don't.
This Patriots team is loaded with guys who have had the chance to develop and grow into good productive players, Douglas, Boutte, Spillane, Ellis, Marcus Jones etc etc.... demonstrate that if you give the right guys the chance to grow and develop they can become good contributors to the team. Fortunately Vrabel believes in developing players, and he has convinced the players that he is behind them and that they will help them turn themselves into good player's, and that's why guys like Swinson turn down offers from other teams to go on their active roster, and stay on the Patriots practice squad instead. The added benefit to this is that a team has much more freedom to address real needs in free agency, as developing your own players leaves much more cap room to play with.