Listening to Moses (and people with disability)

We read the beginning of the book of Exodus in shul yesterday, and I am grateful to Penina Weinberg, my fellow member of Temple B'nai Brith, for bringing forward Professor Julia Watts Belser's discussion of Moses in Loving Our Own Bones: Disability Wisdom and the Spiritual Subversiveness of Knowing Ourselves Whole. 

There's a longstanding tradition of commentary on Moses' saying he was "slow of speech and tongue" (4:10). Older midrash has Pharaoh trying to tell whether a prediction that Moses would take his throne away from him was true and placing before the baby Moses a gem and a burning coal. The theory was that if he were greedy and ambitious, Moses would reach for the gem. Instead, he grabbed the coal and, as babies do, put it in his mouth. Thus, the rabbis explained, he burned his speech organ, explaining his reluctance as a grown man to "speak to the Children of Israel." That is why his older brother Aaron has to interpret for him, to the Jews and to Pharaoh's court.

Whether for that reason or for something congenital, Moses was a stutterer. Belser (Penina says) uses him as a model of how disabled Jews can not only achieve leadership despite their characteristics, but even because of them. So, when rabbinic interpretation jumps ahead to Deuteronomy (where Moses orates for chapters and chapters) and concludes that God must have healed him in the meantime, Belser rejects that interpretation. She, and Penina, and I all like to imagine that forty years later, Moses still spoke with his usual stuttering voice--and the Israelites patiently listened.

Now, here's the further question this raises for me: What happened in the meantime to make it possible for him to be willing to speak, and them to listen?

Was it simply that Aaron (and Miriam) had died, and Moses had no other choice?

Or had he gained a lot of confidence by being a prophet and a leader for all those years?

On the audience side, was it simply that the generation who had met Moses in Egypt had all died out (except for Joshua and Caleb)?

Or had something changed for the Israelites over that time: the experience of living in the wilderness, or of being taken care of by God just as Moses said, or something else?

Most importantly: can we learn anything from the Torah about how to change our own society so that people's differing abilities and disabilities are valued, as part of what they brought with them to Sinai? What?

P.S. I also want to think about big brother Aaron and how he was able to put himself at his brother's disposal after not seeing him for decades!