You know... I never thought about that. I would usually wonder why trainers only have like 2 or 3 pokemon.
I only have 2 dogs despite there likely being 150 breeds. What kind of psycho would horde so many pokemon?
Imagine a charmander and evolutions. Constant fire hazard from the tail alone. That little fuck would spend it's entire life in it's pokeball if I want to have any hope of insurance covering my house.
Actually I feel like insurance just wouldn't cover you if you have any pokemon at all unless you pay extremely high premiums.