Lots of ideas on this one .Ill share my thoughts.When you first get a weaned baby bird,and your the one taking it out everyday,cleaning its cage and feeding it .The bird knows your not going to hurt it.If you want other people to be able to handle it ,it has to be taught[its not a given thing with birds]This has to be done on a regular basis.Lets say you take care of the bird and your husband occasionally wants to see him and the bird freaks out [the bird doesnt know HIM !!] then you hear its a mean bird or it only likes men or women.I think alot of the problem [and there are exceptions]the birds are misunderstood.They have never been taught! Yes if your mean to a bird for whatever reason ,they will remember and can have problems with similiar situations. If you want a interactive bird you have to do the work.
I think thats the problem with alot of the rehomed birds.