Many of the authors you listed there, such as Tolstoy and Twain, certainly deserve high praise for their literary accomplishments. But Capek's R.U.R. was absolute dreck, to be quite frank. It was nothing but overacting, gaping plot-holes and general absurdity. The characters seemed like bizarre inhuman caricatures who engage in nonsensical behavior.
Readers are introduced to "Helena" at the beginning of the play, who all the male characters immediately fall in love with at first sight. In Capek's surreal vision of the world, this is not even a source of any drama, and all the men are perfectly happy to let her pass them over in favor of Domin, who she marries. From there, the play jumps immediately into a robot uprising several years later, most of which occurs off-stage, and ends with the off-stage eradication of humanity. The robots discover that they cannot reproduce without the aid of their human creators, but this dilemma is solved when two robots fall in love with one another. A ham-fisted reference to Adam and Eve glosses over the unsolved reproductive issue, and all the robots presumably live happily ever after.
I cannot speak for the rest of Capek's work, or whether these issues were merely a result of a poor translation, but I cannot call R.U.R. a great piece of literature from my own personal experience.
