The inconsistent shooting really isn't exclusive to this one game. They simply don't have guys who will make you pay often enough if you dare them to shoot. Olynyk is probably the best overall shooter among the starters which shows how limited they are.
Bass probably has the most consistent jumper out of everyone on the team. The other players haven't developed anything close to that level of consistency. Since they also don't have any other reliable go-to moves, they really need to make their bones by shooting better.
And Sullinger, please stop taking 3s!