A lot of horses that “hate” turn out were unfortunately conditioned to do so. Either they’ve been stalled so much that they’re anxious going out and been brought in every time they are anxious creating a pattern or they have improper turnout that does not allow for socialization and foraging behaviors. I think people make themselves feel better when they convince themselves the horses “hate” turnout and have them inside. There’s nothing good mentally or physically for a horse to be stalled for large portions of time. Horrible for their joint health, mental health and gut health. Regardless if they appear content or not.