Right, so in vintage PPB fashion basically you agree with me but have done it in a roundabout way that ensures that it seems like you are disagreeing.
No, but seriously, there's the loan, which let's be honest, was a massive fuck up that most of us saw at the time, and then we can enter into the slightly more speculative parts: at what other clubs do players just disappear for a year only for us to find out like 8 months later they have some strange chronic injury that should be relatively minor but for some reason lingers forever? And, while I know you will disagree with this in typical roundabout fashion, he's gone to Bremen for what reason, obviously? Playing time. Would he have gone if he were promised that here? I really don't think it's such a big assumption to say no...his recent comments and those from his father suggest playing time was very much the issue. He was blocked by Iwobi, Alexis, and Oxlade-Chamberlain (maybe would've even seen Ramsey as a player blocking him too going into this season) here, and certainly more effort could've been made to rid ourselves of one of those players blocking him, and convince him he would find minutes here? (As he certainly should, given our current squad)
In short, we come back to my initial conclusion: we botched it as much as you can botch something like this.
That's not even true, he was doing the business at 17 in the middle of a title race. That you couldn't see it or don't remember it is another issue.