In the wild they would just be in a dark nest sleeping and eating. However, some breeders feel the enriched interaction helps the bird develop faster. Most people think the baby will bond with the owner during feeding but birds actually form long term social relationships with individuals other than their parents. Hand fed babies require special attention to prevent behavior problems since there is no example of normal bird behavior available to the baby. They will need human companionship for their entire lives because they do not always identify with other birds.
Hand fed babies can make poor breeders or parents.
Preventing problems is important since sending your baby to a breeding facility if it doesn't work out, is not an option. If you have a good avian vet for advice and are able to stay home during the day you might want to try hand feeding your baby bird. If you are considering adopting a previously owned pet, you may find the bird timid or even reluctant to be handled by you in the presence of his owner. But in another room, you can tell if the bird is comfortable with you right away. If the bird you are considering is not tame or screams or threatens to bite, ask the seller how long the bird has been in his care and how the bird has been handled.