The "Spiegel" article is a good one - but only on a descriptive level. It does not ask: Why is that?

IMO, the term "Americanisation" misses the point. The reason for this apolitical election campaign lies within the current political situation in Germany: There can hardly be any doubt that the next government will be led by the CDU/CSU. Consequently, debate over issues has migrated into the conservative camp instead of, as normally is the case, being held between different parties. But debate between the traditional parties can not simply stop, for that would violate traditional patterns of mass media perception of politics. Therefore, in this part of the "discussion", issues have vanished and personality prevails. The real issues - tax reform, social security, security policy ect. - are being debated within the CDU/CSU and FDP camp, and that for a reason (an awkward one, but still a comprehensible reason).