A condescending tone reveals a level of immaturity in a person.
It's rude and shows immaturity and selfishness.
Often immaturity rises from a lack of self-respect or insecurity.
Adolescence is a time of moving from the immaturity of childhood into the maturity of adulthood.
Its striated plumage also favours this view, as an evidence of permanent immaturity or generalization of form, since striped feathers are so often the earliest clothing of many of these birds, which only get rid of them at their first moult.