Is it worth delaying a PhD thesis submission to gain more publications?
I think you should consult with your sup regarding your situation to complete the Ph.D. and your future. Are the publications important for your graduation? 

However, I think I have a more important question: Are you on scholarship or financial constraint? Can you live on your scholarship while waiting for the publication? 

If this is not the case, I would suggest that you should submit your thesis, regardless of your publication status. After you submit the thesis, you can still be in the circle, such as doing casual teaching, marking, etc.   

However, if your scholarship allows you to do that, then yes, you may wait. Nevertheless, publications while doing Ph.D. are not necessarily the only thing for you cross the bridge, but it is the experience. It is very difficult to get your paper accepted especially in a high-rank conference if you hardly get any proper supervision.  With a good team, you may find publishing easier than right now.