"FWIW, I answer lots of easy-to-find-the-answer questions. I agree that people should be allowed to ask & answer them. I agree that help from others is relative to whether someone repeatedly makes little effort. I still think that SO and english.stackexchange.com have the right approach by encouraging people to make an initial effort, and to describe to others what they have already tried. And I think that lack of such info can be a reason for closing. And yes, closing questions, like downvoting them, can improve question quality. And encouraging users to ask Emacs first helps them, IMO."
I agree with all of these points except for the two sentences about closing. A closed question is a question not wanted on site (duplicates aside). If someone asks a question which they find not trivial, but it gets closed because of not enough research, it says "we do not want ignorant questions like yours on our site". Downvoting says that "the question should be improved", this is not the same thing.
This is fundamentally different from duplicates : when we close a question for duplicate, we do close it (but not in a "we don't want your question here" way, in a "let's make this question a path to the good answers" way) and we explain to the user that "this question has been asked before, it has a lot of good answers already, so he will be better helped by reading this other question than by waiting for a quick answer here". The implied criticism of "not enough research" is probably perceived, but it is still implied.
Let's not forget that ultimately, all stackexchange does is rephrasing documentation, over and over. That does not mean that the questions or answers are trivial. Sometimes documentation is not easily available. Sometimes it takes months of work to deeply understand its meaning. What answerers are doing is not copy/pasting routinely from manuals, it is using their experience and knowledge of the topic to find the very relevant passage, and then rephrase it so that the OP (and future visitors) get enough understanding to solve the problem from the question.
Just a simple test: you are looking for how to do something trivial in a language you are not too familiar with, so you ask
<search engine>. In the results, you have a stackexchange page, and a documentation page. Which one do you read first?
And last, in my opinion the situation also depends on the age of the site: for older sites, such as SO or english.se, it is likely that most easy interesting questions are already asked, and that a user asking a new one should point out how his question is not already answered. This policy helps the user not waste time carefully asking a question which was already answered. But our site is still young, a lot of easy interesting questions (yes, I put the one that you mention in this category) are still available, and they should exist.
 Questions can be closed, editted (by the OP or someone else), and then reopened. But in my opinion, "not enough research" as a close reason does not leave much room for improvement beyond deletion. If the question is unclear, this is an entirely different issue.