Some young people are not happy with the old Gandalf, (who will be much older in the next two films), and the old Radagast. This is simply a symptom of the Westerners growing lack of respect for age. In the Eastern cultures, especially pre-Marxism, the ancient ones are revered. That young viewers want young wizards is odd to me. The Istari are ancient anyway, and so who cares if they look old. It is a serious lack of sensitivity to want wizards to look 35 or 40 and be super strong. That is not the point of a wizard to be a superhero, but to watch, wait and give advice.