Puhh, sorry, this one got long, but please bear with me...
I think the question got downvoted mainly for the same reason, it got closed for half an hour ago. There are no ways to determine a correct answer. As it has been said here:
Because even though there are often multiple correct answers to a question, we do want to be able to evaluate the correctness of answers. If the question is a broad "so, what do you think I should do?" or "what's the best X" or the like, there's no way to do that. The Stack Exchange Q&A format works well precisely because it's Q&A -- not discussion threads.
I am sure you know that, as you yourself answered the above question as well.
So, why exactly has this question been downvoted? I can only theorise (and haven't downvoted), but there are some possible reasons I can come up with:
The question is very short. While this does not necessarily mean a question is bad, on first glimpse, it provides the impression that the asker did not put a lot of thought into it. This, compared with the low reputation of the asker possibly leaves a casual reader of the question with a bad first impression.
Further, the questions starts with a rather unpopular statement. And the questions motive ("I think Blogosphere is a much more apt name for our planet."), is not explained any further.
The goal of the question as you called it reads:
What would it take to get 95% of the human race to agree with and formally recognize this blogosphere-shattering change?
This is a very random number. There is no way to ever prove an answer correct.
Further, the question is tagged reality-check. The tag description says:
[...] Answers to these questions should provide a yes or no answer with supporting information. [...]
"Yes or No."-Now, try to answer a question "What would it take?" with Yes or No. This is not possible (at least as far as my limited knowledge of (the english) language is concerned), meaning the question is mistagged and at least by definition of the reality-check tag unanswerable.
I suppose that some or some more of these traits are the reason for the downvotes.
This maybe a rather odd comparision, but another factor that could improve the likelyness of a passers-by to downvote is closely related to the broken windows theory. Let me explain:
The theory says:
Consider a building with a few broken windows. If the windows are not repaired, the tendency is for vandals to break a few more windows. Eventually, they may even break into the building, and if it's unoccupied, perhaps become squatters or light fires inside.
This might be a far fetched comparision that fails in detail, but what I am trying to say is, if a user sees a question that left him with a bad first impression and he then sees that the question has already been downvoted ever so often, he is more likely to press the button himself as well, as opposed to when he would be the first to vote and express his opinion.
You are absolutely right, when you say
A click on the downvote arrow and moving along to the next question doesn't help the asker improve, either the question or on the personal level.
But the maximum length for a comment is 600 characters, which is not much if you would like to give an extended explanation. And it might not even be possible, as some of the points stated above (like the reputation and question length) are not really somthing wrong or bad.
So probably, even though I do not share this attitude, those voters just could not be bothered as they weren't thinking the question would be salvageable.
But after all, this can only be said with certanity by the downvoters themselves.