Elf Sternberg

Its been my experience that theories like Kubler-Ross' tend to have a lot of caveats put in by their creator; AFAIK she did specify that not everyone goes through every stage, nor that it is necessarily a linear progression.

Unfortunately, most of the time those caveats get lost in the dust when a theory reaches popular attention, so you get "Hey, there's this research that shows everybody goes through these 5 stages!" and a one-page handout showing the stages in progression, 1-2-3. So I think the problem is more in how it is applied, something the theorist has little control over, than in the theory itself.