What I think happens is that a publication gets launched by some hard-core enthusiasts who are really into the subject matter; with them, their publication is a labor of love. But eventually the publication grows, and the original core of enthusiasts realize they need some help managing the now-larger beast. After all, their expertise lies in the subject matter, not in the details of managing a publication itself. So, they hire on folks who know how to manage pubications, but are not necesarily knowledgeable about the subject matter.

And where do they find such people? Guess. Folks schooled in the liberal arts. Non-science people. IOW, people who more than likely were raised in leftist academe.

Eventually, the publication managers take over the pub as the original cadre of enthusiasts retire or move on, and their world view then drives pub content. This is what I think happened to Scientific American.