The only thing I can say is that there is definitely a correlation with bad shooters being bad FT shooters in real life. I mean look at players like Dwight Howard, that guy can't shoot a jump shot or a free throw to save his life, another example, Jason Kidd, was an average jumpshooter over his career and posted an average FT rating, Steve Nash/Ray Allen great jumpshooters and great FT averages as well. Shaq terrible jumpshooter and even though we know he practiced his free throws all the time never really got better. Just some examples. But I do also see what you are saying as well. In fact I would say it would be more realistic for a larger player 7footer or so should be required to have a good jumpshot in order to have a good freethrow rating.