The question is why where they rejected? My wife is a researcher and does a fair amount of peer review and sometimes she has to reject papers, not because their necessarily wrong, but because they're so badly written its hard to tell if they're right or wrong. Other times the research and paper is fine, but the conclusions are overstated, for example claiming that A is better than B, when all they've actually proven is that A is not worse than B. Other times it's great paper in every way, but covering a topic that really isn't relevant for that particular journal.
Basically there are lots of reasons to get rejected that have nothing to do with the quality or validity of the research.
One of the problems with peer review is that behind the veil of anonymity people can get away with such presumptuous nonsense. You are part of the problem.
An extremely technical paper on centrality metrics in a clinical journal is not the right audience.
I suggested there were ways to approach writing it for that audience, but they'd need to extensively rework the paper. The reason I know that? I've done the same thing, for the same journal.
Basically there are lots of reasons to get rejected that have nothing to do with the quality or validity of the research.