Emilio asked that I turn my comment to an answer, so here goes, with edits, having responded to various comments:
Imo, what one should also be considering when voting for closure or deletion should be if it is a question that could often come up in search engines . I learned through the discussion here that closure does not take a question out of the field of engines and also that answers are still alive as far as reputation goes. If there is already a good answer, then I would not delete the question, reasons expanded below.
When I answer questions which are candidates for closure or even deletions, this is my criterion, that a clear answer would be found even for a nonsense question , if it is nonsense that may be often asked by high school children interested in physics.
Low quality posts may reflect an average non physicist's ignorance , those are the ones that I consider worth answering, to clear up confusions. A confused post is different than a post where somebody proposes own theories, those yes, I feel no compunction in their deletion, and the same for answers. But naive questions imo should be treated gently, particularly of new users of unknown sophistication in physics. It is possible to educate people, and one of the purposes of this site should be physics education.
I would set the question above on the naive side, somebody who has not understood special relativity.
If there is a good answer to the question candidate for closure, and the question is on the naive or confused side, then I would not delete it.
Now low or high quality judgement is peculiar to the comprehension of the reader. A naive question can be judged low quality as also a confused one. My preference is to be gentle, as we are now advised also, and to try at the same time to educate a general audience.
As physics becomes more and more esoteric due to complex theories, it is necessary to develop narratives that are correct and simple, understandable by people with just highschool level physics, again in my opinion. It is the level of the answers that characterizes the quality of the site, not the question itself, as far as I am concerned.
Not to forget the discouragement of the heavy guns on a new user.
I am reading a fiction on an apocryphon with a lot of bible quotes:
"Which of you, if your son asks for bread, will give him a stone?"