Agreed, why bother signing players u21 with enormous potential and develop them as a group suffering short term results for long term success and then WANT to sell them?
Barca had Xavi Iniesta and Messi come through together as well as Busquets etc...all through their academy with years playing together.
We are buying in these players like Stones and adding them into what the u21s produce like Barkley and will see the effects of their development together over time.
We should want to keep them ALL but of course if one does end up leaving Martinez should replace them with 2 more players u21 with similar potential levels.
Agree with the principle mate and that 'squad system' method is what Martinez is trying to build.
Like you, I just don't get why fans actively want to see us sell our better players.