Sometimes that damage can be undone with very careful training and resocializing...
I don't think interaction with people is bad for parrots, but it shouldn't be their only means of scratching their social itches.
How are you deciding what is "good" for a parrot?
A preference for humans is certainly not natural for a parrot. However, I don't think there's anything natural about the way most humans live their lives, and I quite like modern technology. Perhaps parrots similarly appreciate being in a safe environment with loving caretakers. (Or perhaps they don't—but I don't see how we could know either way.)
Put another way, I'm not convinced that living in the wilderness and having to scrounge for food and avoid predators is necessarily a better life than living with a loving human who cares for you. Both are certainly imperfect in different ways, but unfortunately we can't ask the parrots which one they would prefer.
What is less meaningless is the idea that animals should be able to fulfill the full spectrum of their natural behavior. For parrots that means conspecific company. People don't talk like parrots and don't act like parrots. That is consensus among experts, by the way.
Sure, there's history there. But I don't see it as "damage". He is clearly quite happy when he is with his people.
His other great delight is figuring out how to open his palace in the morning to get out early. Every time he manages it he struts around for quite a while looking like he just won the Superbowl.
One of the most objective criterion for animal welfare is how much of their natural behavior they can fulfill. People don't talk like birds, don't act like birds. Only parrots of pretty much the same species can fulfill some things. I'm not even talking about mating and all the behavior around that, more like everything else.
That's pretty much the only criteria I'm really interested in.
All our birds have other birds of the same species with them, which they all do enjoy I can confirm. Well, generally :). When one is being obnoxious to others they can flee to their people.