“ Historicly, we have had plenty of rl groups like the Taliban and the Puritans who supressed anything which was in any way fun. What if there was some group that was the opposite? (which in time would cause problems of it's own for the civilians under their control.)”
“ A modern kingdom still strictly adheres to ancient traditions due to their long forgotten deity getting annoyed at the moral decay, appearing as an AI Singularity and forcefully correcting everything it sees as morally wrong. As such, even though the weapons and technology have improved, the culture hasn't.”
“ Legends abound in some places about ancient landforms (Islands, Peninsulas, Mountains) that dissapeared long ago in towers of glowing energy. (See Any Unnatainable Glory entries for more info)”