I think it's most important that chicks be raised well, no matter who does it. It's most likely for a compassionate owner to be the one who provides that good care. But an experienced keeper or breeder can turn out really friendly chickens just by being humane and aware of the birds emotional as well as physical needs.
By emotional needs, I'm talking about what they don't experience more than what they do.
Not being handled roughly, not being scared frequently.
Regular noises of living present for them to get used to without becoming threats. For example:
Regular noise of dog barking
vs
Dog barking and snapping at the wire between them...
The second scenario is one that will teach chicks to startle at the sight of dogs.
Likewise, well meaning keepers can traumatize their chicks with handling. Most problematic, they often miss seeing what they've done wrong. Whereas a different new keeper may have a more observant and sensitive manner with their chicks, and get a completely different result.
One of my two most friendly hens came from a breeder who had an aloof but competent manner with her birds. Susie Q always wants to know what you're doing and follows us around.
The second friendly hen I raised myself, she "talks" to me with her low whistles when she sees me.
That's out of a LOT of chickens we have raised. I don't try to make them pets but some make themselves into pets. Most are just happy to be about their own business, and I'm happy to watch them without them acting scared of me.
We raised most of them in our hang-out outside areas, like on the back porch, but with a hands-off approach. So they got used to everything without thinking we were going to pounce on them. In that way, even our Leghorns turned out relatively calm.