Fishbone said:
I'd say that with so many foes like giants, monstrous humanoids, full BAB classes, magical beasts, dragons, and abberations having so many HD, a good Fortitude save(by virture of dice of class) and creatures like undead and golems being immune that the Fort spells are usually the most niche/least used.
Outsiders and dragons have great saving throws all around.
Animals, giants, magical beasts, plants, and vermin have good Fort saves.
Aberrations, fey, oozes, and monstrous humanoids have weak Fort saves. Note that, contrary to popular conception, the ooze type confers no innate immunity to death effects.
Undead and constructs not only have weak Fort saves, but no Con score either. True, they're immune to straight death effects, but they can be destroyed by anything that can destroy an object.
Of course, the question can be taken a number of ways. Is it asking if monsters' Fort saves too high relative to their other saves? I would say no, they're about the same.
Or is the question really not about their Fort saves being too high at all--is the real question "do save-or-die effects fail too often?" That's a different question altogether. I might agree that monsters have high Fort saves, but that doesn't mean I think save-or-die effects should succeed more often against monsters. Sorry, tough encounters shouldn't be short-changed by a player who thinks it'd be cute to try and one-shot my BBEG.