The city is an interesting place - an ensemble of people from all around the world, and even from different times (though the 20th century seems to be prevalent).
Their occupations, genders, beliefs, and everything else seems to be as diverse as possible, except one thing: there just aren't any great, or probably even decent, artists. Writers, actors, painters, film directors - all mediocre at best, while there are certainly great engineers and scientists ("No Mendeleevs, but on a solid international level").
Why is that? Given the whole novel is a reflection on the life of the authors in the Soviet Union (it is, isn't it?), why are there no great artists in that world? Are they not chosen to be invited there, or what?