MD80Fan. You are not wrong, the airplane could have been landed inside 100 miles by making an emergency descent, perhaps much less than that. Getting it down is usually the best choice for smoke and flames in the cockpit, indeed that is what is written in the emergency procedures and checklists. Why this crew did not do so is not something we can answer and might never be able to. The CVR should shed some light on what went through their minds but I doubt that things like what cargo they were carrying or a fear of being criticised had anything to do with it. They were experienced professionals and if there was something they could have done better, we can all learn from what happened and perhaps save some lives in the future.
Even for the most experienced and professional crew there is a period of denial. "this can't be happening to me!" before accepting it and acting appropriately. Sometimes this seems as if the crew is failing to act, although one of the first things you learn is not to be hasty. But there are a couple of situations that absolutely require quick action, such as engine failure on takeoff and wind shear on final. Fire in the cockpit might not seem to require this rapidity but really it does. Getting a 747 down from 35,000 feet in 15 minutes does take effort and the sooner it is started the best chance you will have. Idle power and full speed brakes must be used, then all you have to decide is whether to use the gear or maintain Vne. Finding an airport is not the first consideration.
I remember the Erebus transcript, with the PIC calmly calling for "go around power please" when they were only seconds from disaster and it taught me to always fly the airplane. If I needed to go up or down I made my airplane do just that. Never mind if I looked foolish in the process.