Abandoning vs. further pursuing a rejected paper?
However, given that I ultimately aim for an academic career, I think it might be worth some efforts to get something published.


This alone makes me thing that it may be worth the effort - attempting to enter an academic career becomes vastly easier with some publications under your belt. Don't be discouraged by negative reviews - more than one of my papers has gotten reviews back that are essentially "This paper is bad, and the authors should feel bad" that end up seeing publication.

I would continue to pursue your paper for at least another round or two of submissions, but given it's not strictly speaking what you're interested in, if it becomes a burden either in your classwork or in publishing something you are interested in doing (I had a paper become just such a problem) return it to the shelf.