In this election campaign, Schröder used the old Adenauer election theme of "No experiments" successfully against the CDU, and a minority government with "pick-and-choose" majorities would certainly be extremely experimental.
After all, this is what Schröder did himself. The SPD blocked Kohl's tax reform plans in the Bundesrat with the SPD majority, then once in government (and once Lafontaine was dumped), they implemented something very similar. *Lunatic*, n. One whose delusions are out of fashion.