As a Jimmer supporter, I hate to say this but it looks to be the case. Jimmer has been too generous with the basketball and he's passing up on wide open shots. Jimmer is playing scared. He scared that he might not shoot well and he ends up not shooting well.
One thing that makes good players is confidence in their game. You have to be willing to be the goat. This doesn't mean be a ball hog, this means if you're not confident in your ability, you will play timid. Jimmer at Sacramento looks nothing like the confident Jimmer at BYU.
Look at other rookies. Kyrie Irving started off bad in Cleveland but he kept playing his game even when he was turning the ball over. Marshon Brooks had a 17 point game then he went scoreless the next game and then came back with 21 and 17 point performances. There's others like Iman Shumpert and Derrick Williams.
You can't be scared of having a bad game or looking bad. You're not going to play great everytime you're on the court. Hopefully Jimmer can get his confidence back instead of playing scared and timid.
Contrast Jimmer with Isaiah Thomas. Thomas plays with confidence even though he makes some mistakes out there. Mistakes are going to happen so you can play hard or play scared.