I disagree with your thoughts on real basketball and on training in this game. The main idea of a FCP is to create turnovers. The FCP in this game increases turnovers, simulating the main focus of the defense in real life. Since I began playing, all the BBs have said is that the game is about prioritizing. Training is no different than any other aspect of this game. If you want to train guys out of position, you can. If you want to create certain types of players, you can. There is, however, a need to make choices based on priorities. The fact is, it is the trainers who train players poorly, not the system. If casual players aren't motivated to learn how to work within the system, I don't blame the developers. If there were no good players, maybe, but that is not the case.
In most levels of basketball, the demarcations between positions are quite clear. Even in the NBA this can be the case. Look at the Celtics. What's more, media guides and news media use PGSGSFPFC to classify players. There are many swing men, but you would never see Dwight Howard listed as a guard. You would never see Rajon Rondo as a SG. Yes, basketball is a fluid game, but the vast majority of time during a game the different positions will be fulfilling position specific roles. Having players who can succeed in roles not normally associated with their positions creates mismatches which is why multi-skilled players like Lebron, Dirk, and Wade are so successful. The same applies in this game, I believe.
And it certainly isn't anyone else's fault if your rental monsters don't do the job.
Once I scored a basket that still makes me laugh.