The Pharaoh Has Spoken!
You tell the royal advisor that you wish to be buried in The Valley of the Kings. The tombs in The Valley vary from small tombs that are little more than a large hole in the ground to very large tombs with over 100 underground chambers. Due to the fact that you have many items you want to bring with you into the afterlife, you tell the royal advisor that many chambers should be built, just to be safe.
The reason why the Pharaohs of the New Kingdom were buried in The Valley of the Kings and not in extravagant pyramids was because pyramids were easy targets for robbers! Once a Pharaoh's pyramid is sealed, it is never supposed to be opened again. So while some may think how great a Pharaoh you were every time they laid their eyes upon your pyramid, others will surely be thinking of the great treasures that lie behind those four walls. Even if they do not succeed in robbing you of the possessions you want beside you in the afterlife, as soon as they break the front seal they are disturbing your eternal rest! It would be a disaster if they succeeded in stealing your riches! Thankfully your tomb in The Valley of the Kings will be hidden and not as obvious as a pyramid!
The reason why the Pharaohs of the New Kingdom were buried in The Valley of the Kings and not in extravagant pyramids was because pyramids were easy targets for robbers! Once a Pharaoh's pyramid is sealed, it is never supposed to be opened again. So while some may think how great a Pharaoh you were every time they laid their eyes upon your pyramid, others will surely be thinking of the great treasures that lie behind those four walls. Even if they do not succeed in robbing you of the possessions you want beside you in the afterlife, as soon as they break the front seal they are disturbing your eternal rest! It would be a disaster if they succeeded in stealing your riches! Thankfully your tomb in The Valley of the Kings will be hidden and not as obvious as a pyramid!
But!
If you had decided to be buried in a pyramid, your people wouldn't simply build your pyramid, bury you, then walk away. A city would be created as your pyramid is built. You would have provided homes and food for everyone who worked on the pyramid. That would have been great news for your people as you are creating jobs and letting them make a living. Even after your pyramid was built, the city would continue to exist with some people maintaining and guarding your pyramid while others worked as merchants to create goods for these people. Now your people would not have that opportunity to create a thriving city but you are still providing jobs as tombs don't carve or paint themselves!
If you had decided to be buried in a pyramid, your people wouldn't simply build your pyramid, bury you, then walk away. A city would be created as your pyramid is built. You would have provided homes and food for everyone who worked on the pyramid. That would have been great news for your people as you are creating jobs and letting them make a living. Even after your pyramid was built, the city would continue to exist with some people maintaining and guarding your pyramid while others worked as merchants to create goods for these people. Now your people would not have that opportunity to create a thriving city but you are still providing jobs as tombs don't carve or paint themselves!
Also, just because you are buried in a tomb, that doesn't mean robbers will not find you! Just last week you overlooked the trial of a group of men who were found attempting to break into your father's tomb. Needless to say they have been swiftly taken care of. But you believe that it is less likely for robbers to find your tomb in The Valley than if you were in a pyramid.
You can always place booby traps to prevent thieves from robbing you; such as deep pits with spikes, passageways with dead ends, sand traps and if all that fails you can have curses inscribed on the walls so even if they are successful they are cursed for life. If they are caught, they will be put to death! You are a Pharaoh who likes simple things. You don't need a fancy pyramid to show everyone how great a Pharaoh you are, you will do that through the good deeds you do for your people! Besides, you don't want to stand out and break recent tradition.
You can always place booby traps to prevent thieves from robbing you; such as deep pits with spikes, passageways with dead ends, sand traps and if all that fails you can have curses inscribed on the walls so even if they are successful they are cursed for life. If they are caught, they will be put to death! You are a Pharaoh who likes simple things. You don't need a fancy pyramid to show everyone how great a Pharaoh you are, you will do that through the good deeds you do for your people! Besides, you don't want to stand out and break recent tradition.