Are you interested in getting a two-word answer or in learning about the history of the Soviet Union, the Metro, its view of socialism, ideals, etc?
A brief dismissive answer like your teaches virtually nothing, and the reader does not come away from it any more informed than before. It also does a disservice to HN by discouraging intellectual curiosity. Not to mention that it's against HN guidelines[1], which say:
"Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something."
When you go to Moscow metro, think think how many people had to die building it, repressed while building it, robbed while building it, starved while building it for you to see that beauty.
Had I had a way, I would've ordered all and every piece of Stalinist work to be scraped off, and buried.
You don't see foreigners walking ogling at Svastikas in Berlin metro. It all was meticulously demolished, bulldozed, scrubbed, and buried.
Stalin's ego, turned into an architectural style. That's why.
No need to spend 3 screens of writing on this.