We must always be seeking better rituals and conventions; but we moderns tend to gag at these as stifling to freedom. So we Romantic moderns, especially we Americans, tend to see the issue as simple: rituals and conventions are likely bad, as they are almost certainly not good. Cowboys like things to be so simple. At some level of our common cultural judgments, inherited from our dual heritage stemming from both Puritanism and the Enlightenment, we see ritual and convention as oppressive Catholic priestcraft, or else as either Monarchical or Aristocratic elitist oppression. It is simply in the water here — even if one were to be an American Catholic Monarchist.
Plato was also quite wary of rituals and conventions of a sort that he called “poetry” (ποίησις, from ποιέω “to make, to show, to put/place”), although he practiced a form of it. Although his concerns about convention and “poetry” come from a different place than our concerns about convention and ritual, there are important lessons for us both where his concerns overlap with ours and where they do not overlap.
We are not ourselves terribly troubled by what we call poetry — which we see as perhaps an expensive or eccentric taste at worst, and as a liberating possibility for the human spirit at best. For us, it is decidedly not conventional, or ritual. For Plato, however, Poetry was something very different; when we translate the word ποίησις as “poetry” we collude with an infelicitous conflation of two very different enterprises. We consider “poetry” as part of the “arts”, but the ancient Greeks didn’t have a word to designate the group of disciplines and activities that we would call “art”. Instead, they had the word “τέχνη” (“skill”), which would cover the range of “τέχναι” from medicine to ship-building to masonry to cooking to farming to dancing to making love to poetry, &c.  Disambiguation is helpful. Were we to first trace some of the historical backdrop that occasioned Plato’s concern, we might be in a better place to understand Plato’s Socrates, only then later to see an overwhelming number of analogues in our own world.
Before we look at Plato, then, let us sketch a few outlines of the nature of “poetry” prior to him.