For any 2 important traits, you'll find a negative correlation among NBA players regardless of whether there's a correlation in the broader population. Athleticism, size, length, shooting, handles, etc. That's because you gotta have something to make it in the NBA. If you have the freak athleticism to make it on athleticism, then you probably aren't a deadeye shooter. Same thing for size and length.
In other words, to make it in the NBA as at 6'2 with a 6'3 wingspan, you better have a good jumpshot.