Your student is writing a paper and you think it will be rejected with a probability of 99%. Your student would like to submit it anyway. Would you submit it? Why?
More specifically:
- Is it ok to submit it? Isn't this "bad behavior" because you are wasting the reviewers' time?
- Is it worth to submit it? Can reviews help you improve your paper even when the paper is not ready for submission?
- Is it safe to submit it? Can this damage your reputation if the reviews will be public after the decision is out?
EDIT
In the case above your name would also be on the paper. Would you have the same opinion / give the same advice to the student even if you are not on the paper?