Yeah, it's kind of just misery for the sake of misery. I suppose conceptually it's supposed to test your patience and hearken back to the olden days of gaming, but as you say it's just tedious and unfun.

Ninja Gaiden has some absolutely wild ones where you fight a boss, then the next level starts, then there is a fight in the next level before the next save point. If you die in that fight, where do you think you respawn? That's right, before that boss you beat. There is no auto saving at the start of a level here! Team Ninja seemed to concede that this wasn't optimal though as supposedly Ninja Gaiden 2 has both more generous save points and a "retry boss" function.

But again, playing on emulator with save states eliminates this frustration so please anyone reading this, so don't get discouraged by it!