Who Gets Free Train Rides in Moscow

From A Journey into Russia, by Jens Mühling (Armchair Traveller series; Haus, 2015), Kindle Loc. 1585ff:

While I waited for the elektrichka back to the city centre, I read the announcements on the platform. My eyes were caught by a lit glass box with a notice inside: ‘Categories of citizens entitled to free and discounted transport on suburban trains.’ I read the list, read it again, read it a third time. What was hanging there under a flickering neon light was a compressed history of the Soviet Union.

– Heroes of the Soviet Union (free)
– Heroes of Socialist Labour (free)
– Participants of the Great Patriotic War (free)
– Family members of deceased participants of the Great Patriotic War (free)
– Former underage inmates of concentration camps, ghettos and other places of forced detention, with or without disability status (free)
– Persons awarded decorations and medals of the USSR for self-sacrificing work behind the frontlines between 22 June 1941 and 9 May 1945 (50% discount)
– Persons awarded the distinction ‘Residents of besieged Leningrad’ (free)
– Persons exposed to radiation as a consequence of the disaster at the Chernobyl Nuclear Power Plant (free)
– Rehabilitated victims of political repression (100% discount)

For a long time I thought about the riddle that seemed to link the first category with the last: Soviet heroes rode the elektrichka free of charge, Soviet victims with a 100 per cent discount. I could not make sense of this nonsensical difference.