I'll turn my comments into an answer since they seemed to have some support.
I do not think that we should allow the type of questions you are talking about and I'll explain why by addressing your closed question as an example.
First, I would reject the characterization that all philosophical positions are opinions. I think that is along the same line as the two "philosophical questions have no answers, it's just people arguing about their opinions" and "philosophy can't and doesn't make progress" arguments that people often use to attack the usefulness of philosophy. Both of those positions, I believe, are extremely harmful and just empirically incorrect (it is very easy to find examples of progress in philosophy).
However, I will grant you, for the sake of this question, that all philosophical positions are just opinions. Even still, that doesn't mean that any opinion on any subject is a philosophical position, or any act of giving an opinion is an act of doing philosophy, whether or not argumentation is involved.
If I were to ask my friend where we should eat for dinner, she could be inclined to give me her opinion. That doesn't make the question of where we should eat a philosophical question, nor does it make her opinion on where we should eat a philosophical position. Even if she went a step further and argued for why the sushi place is better than the Mexican place, that still does not constitute a philosophical argument grounded in a philosophical position about a philosophical question. So it is clear that some opinions are not philosophical positions, even if we grant that all philosophical positions are just opinions. Subject matter is a necessary criterion, but I will also argue below that it is not a sufficient criterion.
Granting the above, we have that some opinions are philosophical and some are not and what we need is a criterion to determine whether or not one is. I would argue that suggesting a criterion along the lines of "dealing with philosophical subject matter" is still not enough to make any opinion a philosophical position.
As per the example I gave in my comment, about asking a room full of mathematicians about whether they use graph paper or college ruled paper, even if each mathematician gave a five minute presentation about the advantages and disadvantages of each type of paper, that still is not a mathematical argument about a mathematical subject, or in other words, it's not mathematicians doing mathematics. So, likewise, I do not agree that asking a room full of philosophers (not that that's what this site is) whether or not they find a concept useful is a philosophical question or that their opinions on it are philosophical positions on a philosophical subject. It is not just the subject matter that turns any opinion into a philosophical position.
So all of this being said, even if I were to grant you that all philosophical positions are just opinions, not all opinions are philosophical positions, and the question which you were asking is one whose answers do not qualify as philosophical positions, they're just regular opinions. Honestly, if you disagree with my argument I would be open to a rebuttal, I would specifically want to know what sort of criterion you could propose that would separate "where should we eat" type opinions as well as "what type of paper do you use" opinions from "do you find this concept useful" opinions. It seems to me like your question is just a unary version of the binary what-type-paper question, as in your question wouldn't substantially change if you were to ask "which concept do you find more useful, x or y?", the only thing that would change is the arity of the judgement being made on the subject matter.
Whatever anyone thinks of my argument, an issue we can all agree on is that there is no objective way to answer the question you posted.
This site is designed for concrete, explicit questions and objective (or as close to objective as possible), factual answers. If you are asking the users of this site (the majority of which are not practicing philosophers) what their opinion is on whether or not a concept is useful, there is not any criterion that will make one answer better, or more objective, than the others. As I had said in the comments, they're all equally objective, because they're all answering the question "do you find this useful?". That means there is no criterion for selecting a correct answer and furthermore there is no future utility available for someone coming to the site looking for an answer to this or a related question. Any sort of chosen-as-correct answer would be up to your personal opinions on which argument you liked best, not on the veracity of the answer which is what this site is supposed to be aiming for.