why narrator call the 2 boys childish and artless

both the boys nicola and jacopo were childlike and very innocent and naive. their smile was steady and engaged people stare at them. they were enthuisiatic and jovial and full of energy when the author met them. they never pretend to be someone else and they were far from cleverness and cunningness and never decieved any one and they were of very small age, very tender age. hence the narrator calls them as childish and artless...