Cyclists who ignore red lights, why do you do it?

I cycle, and always wait at red lights. You wouldn't go through a red light in a car, why do you think it's acceptable when riding a bike? I've heard the argument that it can be safer to pass the line and keep moving slowly to avoid coming to a halt and to get ahead of the traffic, but I'm talking about when cyclists just sail straight through the light as if it wasn't there. I'm curious to understand the mentality.