I agree in most cases but not necessarily with catch and shoot specialists. For those players there really isn't a direct correlation. Their good years and great years are for the most part, random. Take Korver for example, 2 of his 4 highest % seasons came on his two highest attempt seasons. But also to your point his best season was his lowest attempt season. If we got someone like Joe Harris, I really don't think his percentage would dive that much taking a few more threes a game. Then again, when these elite shooters are shooting 45% and above, there really isn't much room for improvement. Odds are it does go down, but I don't think it would be due to volume.
No I was here for it. Kyle Korver has embraced being role player since day 1. Most experts agree that's why Melo is still not in the league. I think there was a recent video posted here where Billups talks about it. Last season Melo shot 32% from 3, which is a far cry from the 40% I'd expect from Korver. Also, you wouldn't see Korver apologizing to the bench for passing up a 3 to take a contested 2. Korver is a great shooter, but a lot of that is knowing when to shoot and when not to. How many times did we see Melo pass up an open 3, pump fake, then shoot the contested 3? Melo doesn't know how to shoot if he isn't creating his own shot off the dribble. Korver moves a ton off the ball to get his looks. I get your point, we looked awful with Melo. In all fairness though, I think Bzdelik had a lot to do with that as well. The team started clicking when Bzdelik came back, not when Melo left.