i know that and that is my point , why have a cramped tomb in a pyramid to spent the rest of erernity that you cant even fit a decent sized statue in than a nice roomy tomb with loads of pretty pictures on the walls and more gold and food that you can poke a stick at. i know what i would choose, and i suppose that the valley of the kings would be better security wise than a pyramid, which as you will know sticks out like a sore thumb on a foot.

Security was the main reason that the pyramids were abandoned as tombs--after some very obvious tries that were robbed, Pharaohs looked for a more secure place to built their tombs. The VOK was a good choice, actually--close to the main city, easy to guard, relatively easy to dig, and could be hidden. Although the Great Pyramid is not decorated interiorly, a few years later, the interior of pyramids were covered with hieroglyphs. Also, any treasure and other comforts the Pharoah might need in the afterlife was stored in auxillary temples and small pyramids. The actual burial chamber was really not that small--about the size of an average living room.
It's very easy to see the progression of burial tombs. Starting with the pre-dynastic pit-burial, to the mastaba, the step-pyramid, then the true pyramid. They are quite obviously tombs, and the thing that most people overlook is the fact that there are many pyramids in Egypt--in all cases tombs, and nothing else.