At the very outset, let me share my own quick assessment of your cited examples (your own posts) based on the original forms (without looking at any of the comments, at first):
$\bullet$ Are large samples always needed for a Z-Test?
There were improper usage of notations and terminologies and some misunderstandings. I feel a bit hesitant seeing words like good too.
$\bullet$ Do you lose information when you encode numerical columns with two values?
This seemed to be also not replete with proper usage of notations; in fact it was outright ambiguous which prompted it being closed. Finally you edited it to provide better structure and I was one of the reviewers who voted to reopen it.
$\bullet$ Calculating the probability my observation, $Y_i$, is drawn from a random variable $X$?
Again it is infested with the same problem: improper usage of notations and terminologies.
However, I do feel all those queries were not bad; they were sanguine and intended to be valid queries - unfortunately they were not adequately articulated, at least in the original form.
We don't know everything. That's why questions arise (that's basic). However, there is a certain extent of knowledge that we apparently take for granted as if we were well versed with those notions and concepts. So when we mould a query resorting to the language from that for granted knowledge that we acquired (might be a quick reading of a blog, site, video etc.), we are certain we have raised a legit proper question.
But things go awry when we see responses from people that implicitly attack that for granted evident knowledge. It might start to seem nitpicking to us: instead of answering in a general way to our evidently clear queries, their comments are vacillatory and moving back and forth.
However, then a mature way to react is to take a step back and try to read between the lines of the comments: what are they are trying to air and communicate? Then we can realize what we have been regurgitating might not be correct. The notations and handwavy concepts might need to be altered or outright restructured.
Then we would be able to conclude while the query could be genuine, the way it was raised proved to be its own impediment in getting a good concise answer.
Comments are absolutely necessary. When it gets long, chances are OP is not able to clearly provide ample explanation of what they are asking: the question could be sensed, but a proper useful answer warrants an explicitly clear post, even the confusion that evoked the question at the first place.
Users like Christian Hennig, Tim, Dave, utobi, Sextus Empiricus and all other respected users could have easily dissuaded from interacting and commenting for the sole purpose of eliciting further details and informing you of any misconception. They didn't. Why? Because they understand the value of this community and the site's goal: create a repository of high quality contents: be it an undergrad homework, a research based query or an industrial programming query.
Finally you were able to receive a good answer to one of your posts thanks to those interactions.
Seeing comments as response instead of an answer that solves everything can be indeed frustrating. But for the latter, you need the former in the light of the perspective added above.
One's knowledge can be limited, what I think is correct need not have to be. Those long comments help to remove those misconceptions.
At the risk of sounding like a broken record, I would assert comments are quintessential. You need to be patient.
[It takes days for me to sometimes understand something, takes hours for me to sometimes solve a problem which when seeing the hint/solution showed me how my approach was wrong. But instead of getting frustrated, I take a break and try to learn the necessary materials needed or other things.]
I appreciate you reacted rationally by asking a meta question rather than ranting at those users (I have witnessed many things during my not so long stay here).
To answer your titular question, I am of the conviction that such kind of tag is not necessary.
soft-question
tag on mathematics stack exchange, which does make a material difference to the success of a question. math.stackexchange.com/tags/soft-question/info $\endgroup$