So much knowledge is lost to history. Perhaps the basic reason why Sumerian clay tablets and cuneiform are thought to be the start of writing is that no one else that wrote before had a good portable medium for writing that would last the ages. It may not be simply coincidental that the first writing discovered in history started where there was clay for tablets and writing hard copy followed by a recession of sea level and desertification of Sumer and Ur so people would leave and writing would lay safely buried in sand until discovery. Perhaps that was natural selection and writing on portable mediums like goat skin faded away in weather at some unknown location. History does not provide us with knowledge about content of all of the crude poems publicly recited in Athenian Greece of Plato’s day- maybe some of it was quite vulgar and luckily lost to posterity.
Yet of poetry that existed then (and I am not an expert on that or even on Plato’s writing), I believe Sappho and Pindar were the greatest of the classical era. Poetry though usual was in the form of plays perhaps, and some of the plays of the majors performed then may have been offensive politically and socially to Plato. Since Plato wrote prose- quite non-lyrical, he may have regarded the natural divide between himself and lyric poets in literature more along the paradigmatic axis (meaning) rather than the syntagmatic axis (of form). I doubt that if a lyric poet of his day wrote an ode to oligarchy (Plato-Socrates preferred oligarchy over democracy) that Plato would have been so peeved.
Democracy definitely has problems and runs toward irrationality on occasion. Plato’s Republic (or that of Socrates) was an ideal state comparatively, in theory. Someone wrote that the French would say that some things work in practice but not in theory- The Republic of theory may not alternately work in practice. Plato and Socrates would have wanted society to at least work for an ideal state however, and I can sympathize with the concept that the United States would be a much better place with more logic, understanding and effort to make an ideal state rather than to just it go and trust in the blind, invisible hand of capitalism. Seventy years after the Green revolution people continue to starve periodically on Earth- should one just rely on Adam Smith’s paradigm to relieve famines or to react to them?