I've made several edits to this question trying to focus it for this site. But rather than guessing what is focused enough, could you please tell me how focused it needs to be? Even having some suggested wording would be helpful.
The problem is that each actor may have a different reason for altering their accent and that the community believes there is not a common answer that would apply generally enough to answer the question when asked about actors generally rather than about specific actors. See: Is the "needs more focus" close reason a catch-all?
I'll post a competing answer to my own, so that votes can help me understand which is the right view.
I've been told that the real reason my question was closed was not about focus, it was because the answer was obvious and the question wasn't interesting