*Lunatic*, n. One whose delusions are out of fashion.
Some steam locos survived in regular standard gauge serivce until 1988, not in small part due to the oil crisis. Many locos survived even after that thanks to military thinking (maintaining strategic reserves). Note that not just in East Germany but in most of Europe, the steam era lasted much longer than in the USA, for example, until 1977 in West Germany.
Steam locomotives need a major and potentially very expensive overhaul every few years, so preserving locos in working order has its limitations. But the former East German locos are indeed disproportionately represented among currenctly active steam locos in Germany (and neighbouring countries – some got to owners in Switzerland or the Netherlands). Some survived inactive in shed, for example the one below on a photo in Dresden main station in 1977 is today in Dresden's museum depot:
Preserved steam locos are indeed used in period films. Not always correctly. In The Last Station, a 2009 film about the last years of Tolstoi, filmed in Eastern Germany, you see a steam locmototive (f.e. 0:12, 1:22, 1:41 and 1:49 in in the trailer below) which is not a broad-gauge Russian loco but 89 6009, an old Prussian loco preserved in Eastern Germany...
Reminds an episode from this movie: