What is the advantage to the organism given by decreased insulin release during sympathetic stimulation?

I'll try to keep it simple, but if I overdo it let me know and we can get more specific. When you hear sympathetic, think "fight or flight" -- these are basically times of stress for our bodies. To fight or flee, our body needs energy. Most of this quick energy comes at the expense of glucose. Insulin promotes the uptake and storage of glucose and shuts down glucose production by the liver. We don't want to do that in times of stress -- quite the opposite actually, we want to mobilize our glucose stores so that it's available to make energy.