A lot of the best Constructivist stuff, like Tatlin's Tower, was designed for Petrograd, not Moscow.No Russian constructionist proposals? That whole 5 year post revolution period was rather interesting, at least till it all went back to classical design.
The Ministry of Labor by the Vesnin Brothers was designed for Moscow, though i was surprised that the Pravda building wasn'tA lot of the best Constructivist stuff, like Tatlin's Tower, was designed for Petrograd, not Moscow.
Do concur that it's interesting how the Soviets preferred giant pseudo-Roman wedding cakes over the modernist and "revolutionary" stylings of Le Corbusier or Rodchenko. You could argue that this speaks to a desire for legitimacy by wearing the clothes of older states, but there's probably more mundane reasons ultimately--Modernist architecture is quite hard to sustain in an agrarian nation.