My problem with this discussion is that I wonder about the correlation between votes and quality. Admittedly I can only read fairly elementary topics. But I find that questions that give me a lot to think just get downvoted, and I also find wrong answers at the top of the votes. And the vote ordering is often not the quality ordering (when I think I can estimate it with fair reliability).
The problem is that science has never been a matter of opinion, or of vote. The usefulness of vote is more sociological than scientific. Interestingly, the rep gives you a right to manage, not to decide on scientific issues, which is probably a good thing. But it is also a bit of a problem since users can confuse rep and scientific reliability.
There is also the problem that quality is not easily measured. So many users think that a formula is an explanation ... sometimes they do not even bother defining notation, assuming some universality of it. Ther is also the opposite: answers by someone who has an opinion though he does not really know anything on the topic and does not have half an argument to back his opinion.
Now, as I said, I can only read the more elementary topics, and I have been wondering whether the situation is the same for the more advanced questions.
My guess is that one can talk nonsense at any level, but what is it actually?
Regarding specifically the quality of questions, what matters most is
the sexyness-entertaining quality of the question, not actual content
or preparatory work. I will take the example of two questions that are
exactly on the same topic, but were not flagged as such:
Origin of motion and relative speed of bodies in the universe
Why are there no asteroids or meteoroids with relativistic speeds?
The first question was mine, actually my fist post on physics.SE after
doing no physics for more decades than I care to tell.
It took me a long time to write that question as I was trying to
understand first what issues could matter, what kind of data and
question might be sensible.
I was very lucky to be upvoted once, and to get a nice answer.
The second question was asked 2 month later. It is exactly the same
issue, presented as a disaster movie. It was not detected as
duplicate and attracted much attention and 20 upvotes.
So should I try to ask questions as a scientist, or as a showman ?
The other issue, directly related, is the questions removed as
duplicate. First, it is inconsistant (see above) and sometimes
inaccurate. Answering old questions is a waste of time. I know as I
did it more than my share. Thoses answers do not get votes or
comments, and I personnally hate writing for a black hole.
So the practice of stopping duplicate question is just the best way to
ensure that further input will not come, of that a different
perspective will be avoided. What would have happened if the second question above had been detected as duplicate, as it should have ?
And I am really wondering what is the purpose, and the dangers, of
such a site.