As a hippy-dippy writing teacher, I believe writing is a process. There is no one way to do it. (Which is a lie, the way to do it is to follow all the directions.)
I do occasionally allow rewrites for this reason. Get some more practice in, learn from feedback. Go and sin no more.
The last rewrite I offered to the entire class. 99% of the classes needed to submit work. They needed that higher grade. Only 2% of the class submitted anything. And 50% of those students who turned in new work did worse.
At least I can be thankful there was no grade-grubbing at the end of the term from this group.