Rick has pretty much covered all of the bases. Put another way, burning rubber is a way to heat the tires at the dragstrip for some; a way to draw attention to yourself for others and for many; it's simply a way to see, feel, hear and smell the brute power of your street machine for a brief moment without the obvious risks associated with running it up to its power peak in every gear on the street.
Everyone has their own perspective, but asking why is kinda like asking why someone would own a flimsy,bare bones, 500+ HP replicar with no safety features, minimal comfort and almost no protection from the elements that can easily rocket through a 1/4 mile from a standing start in under 12 seconds when for the same money or less, you can buy a much more "sensible" car that is far better suited to the laws and conditions under which it will primarily be used. Like Rick said, "If you have to ask, you will never understand."
Is the Cobra going to be your first experience with a high performance car, ol' buddy? If so - talk about a baptism by fire
And be careful - there's nothing inherently "unsafe" about the way a properly set up Cobra behaves or handles - its just that the relatively massive power in the small, light car can get you into big trouble double quick if you are not 100% sure what you're doing when you're doing it.
