The reason there shouldn't be withdrawal of report provision.

Let us assume I reported a particular user's posts and say about it and the user meets me in dm and convinced me about the reported post. What next will I do, maybe I will withdraw the report since it hasn't been handled.
This time I am now the judge, which is not supposed to be so.
So it is cool you leave it for the moderators, if the reasons to withdraw it is that it wasn't a bad post, the moderators would be able to decipher it and mark it as a bad report.