Although increasing the number of parameters makes the game more flexible it doesn't necessarily make it more enjoyable for the user, especially the new user.
As a new user, you're given a team full of players that are crap, with a smattering of talent thrown in. When you look at training options, you see that you cannot train only your forwards in inside skills without also training your center, you can't train your center in passing without training the remainder of the team, and you can only train SF/PF in jump shot and one-on-one for outside skills (just examples). A number of new teams notice where their strengths lie, and attempt to either improve those strengths or improve the team's weaknesses.
What happens to teams that start with a great PF and SG and want to train them into 2 great SFs? They must either move the PF to SF, or move the SG to C (for optimal training); OR they could play them both at SF and train them both really slowly in inside skills, while training them alongside a couple SGs in outside skills. I'd submit that this system doesn't necessarily make it enjoyable for the new user, particularly for users who don't much understand basketball (suggested reasoning behind "best position").
I
love this game, and have nothing but the utmost respect for the amazing things you (and the rest for the development team) have done and are doing. But I'm having a really hard time formulating a long-term training strategy given the current system.