I get all that and hear you. What you need to understand though is for a lot of that, he needs game time and only game time. And before you say something along the lines of 'Pep knows best', well, that's what we're here for, to debate these kinda things. Pep is a great manager but he also isn't infallible.
Bringing your own player through the ranks is not the same as buying a ready made guy who's already honed all the necessary skills well enough elsewhere to be able slot straight in - perhaps some fans have forgotten that. You can't blame a kid for missing x part of his game when he hasn't been allowed enough opportunity to use the full flight minutes required to help develop it.