Quite a bit of "BSOD" was the kernel going "Sorry, but all our lines as busy. Please hold". But MS decided to use the same basic framework as a honest to deity

Quite a bit of "BSOD" was the kernel going "Sorry, but all our lines as busy. Please hold". But MS decided to use the same basic framework as a honest to deity BSOD. Thus people were lead to believe the OS had gone belly up when it was actually trashing the HDD thanks to low memory, program trying to load files, and the swap file.