[rajivtiru]

The best heat resistant materials we have available to date are ablative materials. These materials "shed" particles of themselves as heat(kinetic energy) is applied.

It looks like starlite while able to withstand more extreme temperatures, also ablates at relatively normal temperatures. From my quick research, this looks like, this is responsible for its longevity issues.

EDIT: relatively normal temperature meaning a blowtorch vs. a rocket nozzle or re-entry heatshield