Isn't the point hough that Rony (and any other youth player), doesn't have to convince the match going fan that he is good enough but the professional coaches. Clearly, they (and I use they, as I don't believe it is just Pellers) are making their decision based on what they see day in/day out.
I don't believe Sterling is your run of the mill 20 year old, he is a special talent and probably got his break by convincing others of this.
At this point in time, our young players havn't given sufficient evidence to suggest they are ready IMO