The answer is simple: those who were already dominated and thereby denied their basic rights can't willingly accept the domination again, they will fight fiercely to the end against it. As simple as such.
The critical point this guy is missing obviously to state what the divide is, after stating there is a clear divide. That answers many question he raised, above all if it could spread to other regions.
It will not, many in the country faced the domination and know it very much closely. No normal mind will reseek a domination in one's own homeland.
The force behind the domination is backward looking, while the one resisting it are mainly forward-looking and for ending of any form of domination.
We can't ask for domination freely, the reason why many Oromos AND OTHERS are not supporting the backward mentality backed by means of violence in the Amhara region.