Tailgating ....... why?

Here's a question for those of you who tailgate while driving. Please tell me what is it that you gain or perceive to gain from tailgating? Is it really that difficult for you to stay a safe distance behind the vehicle in front of you? Do you realize that when you stop at a stop sign or red light that you should be able to see the tires meeting the ground of the car in front of you so that if that vehicle is disabled you can safely go around it or if someone hits you from behind you will not hit the car in front of you resulting in a ticket for you?