People do need to speak in their own person. A classroom that only corrects commas and never asks what is being said will starve the very thing speech is for. The modern emphasis on voice notices something real: speech is an act of someone, to someone, about something that matters to them.
It is also true that a student who is afraid to speak will not be helped first by a scheme of figures. Courage to say a sentence is part of the art, not an extra. Sincerity, too, is not nothing. A hearer can tell when a speaker is merely performing a form, and distrust is a reasonable reply.
The wish to “find a voice and fix language later” often comes from having been trained in correctness without ever being asked to mean anything. If that was your schooling, the protest is fair. An education in speech that never reaches a claim, a prayer, a story, or a plea has not yet reached speech.
What is true, then, is the need to speak as oneself, and the poverty of a grammar that never asks what is being said. What has not yet been shown is that voice can be had before the care of words, or that sincerity is already the art.