They have bought into the Soviet/Stalinist concept of “socialist realism” where art, literature, and basically all media, have to present life in the Soviet states using only the positives, and either glossing over, or outright denying, the bad parts of reality. While this was initially something imposed upon art, like everything in an authoritarian regime, it spread to everything. Eventually it was just how people knew to act, at least publicly, and it wasn’t really seen as specifically “social realism” any longer, just life under Stalin.

If you want a good example of “socialist realism” literature I suggest checking out Cement. It is arguably the first real piece of “socialist realism”, and the seminal work that everything else was built upon.