That’s a good way of framing it. I absolutely agree that individuals and groups should reflect on whether or not their time is being spent wisely.
Here are some possible failure modes. I am not saying that any of these are occurring in this particular situation. As a naive outsider looking in, this is merely what springs to mind when I consider what might happen if this type of publishing were to become commonplace.
Imagine I am a mildly prominent academic. One day, a colleague sends me a draft of a paper, asking if I would like to co-author it. He tells me that the other co-authors include Yew-Kwang Ng, Toby Ord, Hilary Greaves and other superstars. I haven’t given the object-level claims much thought, but I’m eager to associate with high-status academics and get my name on a publication in Utilitas. I go ahead and sign off.
Imagine I am a junior academic. One day, I have an insight that may lead to an important advance in population ethics, but it relies on some discussion of the Repugnant Conclusion. As I discuss this idea with colleagues, I’m directed to this many-authored paper indicating that we should not pay too much attention to the Repugnant Conclusion. I don’t take issue with any of the paper’s object-level claims, I simply believe that my finding is important whether or not it’s in an subfield that has received “too much focus”. My colleagues have no opinion on the matter at hand, but keep referring me to the many-authored paper anyway, mumbling something about expert consensus. In the end, I’m persuaded not to publish.
Imagine I am a very prominent academic with a solid reputation. I now want to raise more grant funding for my department, so I write a short draft making the claim that my subfield has received too little focus. I pass this around to mildly prominent academics, who sign off on the paper in order to associate with me and get their name on a publication in Utilitas. With 30 prominent academics on the paper, no journal would dare deny me publication.
Again, my stance here is not as an academic. These are speculative failure modes, not real scenarios I’ve seen, and certainly not real accusations I’m making of the specific authors in question here. My goal is to express what I believe to be a reasonable discomfort, and seek clarification on how the academic institutions at play actually function.