Taking a vacation or going on a business trip is difficult. You can't just take the owl with you (especially since in the United States permits are usually needed every time you cross state lines.) It takes a trained person to take care of an owl, and if you have a human-imprinted owl, they may be aggressive with anyone else who comes to take care of them. Owls also like routine, so disruption to the normal scheme of things is very stressful for them.