I think I believe this more than the "trainers get dragged to hell theory. (Maybe its just because I want to believe it). It could explain why you black out, rather than just get out of the situation. The Audino/Blissey healer theory I think is still the most believable, although the Nurse Joy one could work. Maybe Nurse Joy has a sister or cousin or something who takes care of wild Pokemon.I like to think that random Chandelures come to steal the Pokémon's spirits, and Drifloons carry the bodies away. Going through some of the many disturbing Pokédex entries can answer a lot of questions.
^ lmaoThey black out and return to a pokemon center... oh wait, never mind.
Maybe the reason you can't find them everywhere is because they are busy? I haven't given Chansey much thought either, but there have to be some Pokemon that you can't catch. Maybe some Pokemon Rangers catch Audinos and use Heal Pulse after a Pokemon faints.I never gave it much thought till now, but none of the other regions have a spreadout pokemon like Audino. There is Chansey but you can't find it everywhere.
Extending this, what if you breed too many pokemon to get a shiny? Won't the habitat be damaged if number of species increases.I think the more important question is:
What if you catch too many of the same species? You would think it would eventually become endangered; I guess therefore they would become legendary...
Man, that's something to think about.