Posting a question as an anonymous guest user (without having an account) is allowed but for commenting 50 reputations are required.
A guest user (who doesn't have an account) can't accrue any reputation points.
Now, if a guest user (who doesn't have an account) posts a question and if some people respond with cryptic answers or wrong answers then the OP (the guest user who posted the question) will want to comment on these answers.
But, the guest user (who doesn't have an account) can't comment because he/she doesn't have any reputation points.
And if the guest user (who doesn't have an account) gives his/her comments as an answer then the answer gets deleted by the moderators because it is actually not an answer.
The downside of this is that the OP can ask only a question and that's it. The OP won't be able to get involved further in the posting.
Because of this, it is quite possible that the answers to the question posted by OP are incomplete / wrong / cryptic, etc.
And this is not going to help the future readers of the question.
Besides, if some user comments that the question is not clear, then the OP won't be able to give more details about the question (because he/she can't comment and his/her answers will get deleted by the moderators).
Involvement of OP is very necessary to make a question and its comments / answers meaningful for future readers.
But currently, OP can't get involved other than just asking the question.
So, please either allow guest user (who doesn't have an account) to comment also or please remove this feature of posting a question anonymously as a guest user (without having an account).
I have faced this problem myself and that's why I brought up this point. I had created this account mainly to highlight this problem. After the discussions are complete, I will delete all my stackexchange and stackoverflow accounts.
I am not saying that commenting as a guest user should be allowed. But if it is not allowed, then, the feature of posting a question anonymously as a guest user (without having an account) should also be removed.
Note: I am using incognito mode of Chrome. And I have setup Firefox to delete all history on exit.