This seems to me to reflect too literal an understanding of the idea of purification of emotion. That is, it has not simply been a mistake to understand the idea of catharsis in connection to purification. And I want to insist on this idea. The experience of tragedy really does connect to a kind of purification.
Tragedy is not merely experienced; it painfully runs you over, pits you against yourself. And this involves a sense of being cleansed, of being drained of what is unimportant—as in being immersed in a Mikveh, purified head to toe by holy water. The proper attire to wear as we go out of the theater is white. Tragedy takes us beyond fear (not merely to a place where there is nothing further to fear, as Lear’s Aristotle has it). It is as if the tragedy allows one to rise above the trivialities of life and reach, and see, and be with, what really matters. Tragedy brings about a sense of focus. It leaves one solemn.
There is here a kind of cleansing. But the cleansing is a necessary metaphor. (And perhaps this is why Lear doesn’t find it in the literal-minded Aristotle.) In particular, what one is being cleansed of in tragedy, or so I propose, is the very perspective of the ordinary, the perspective from within life, from “inside the plain” (Lear’s allusion to Thompson Clarke); really, it is a non-perspective. In tragedy, one is forced not to safely consider remote possibilities as Lear’s Aristotle has it, but into a perspective on life as a whole as if from without—into looking at life itself as if from the audience's point of view, or perhaps from the reflective perspective of the chorus, which is more intimate and inward yet is closed in unreality and isolated in abstraction.
Even the virtuous person lives day to day in life. Where else would they live? And so even they undergo something by being forced, shouldered, out of life.