I'm sure these Pokemon enjoy the security of having a home. And Hayley takes care of the Pokemon to the best of her ability. Hence the reason she allows people to visit and play with the Pokemon for a fee, I assume she needs the income for their upkeep.

Besides...

[Riley reaches out and takes N's hand, grasping it gently.]

Would I be so insensitive to want to take you to a place of abject cruelty?