The interviewer completely oversteps his boundaries here. In case anybody wonders: "Die Zeit" is Germany's tabloid version of a politics paper (similar in lack of quality to "Der Spiegel"). This interview illustrates whats wrong with these tabloids very clearly: Bias, ignorance and uneducated employees.
Piketty brings up some good points but the interview is painful to read, like dragging a wet mattress up a stairwell.